I have a dataset called ds1 filled with 2 tables Employees and Customers
from Northwind database.
I have dropdownList called ddLastName with the following properties:
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
I have a label called lblDisplay
I want the label to display the Notes column data of the selected item in
the dropdownList.
My code is causing a NullReferenceEx ception.
Can anyone find out what is the problem please?
------------------------------------
Code: ----------------------------------------------------
<%@ Page language="c#" Codebehind="Web Form9.aspx.cs" AutoEventWireup ="false"
Inherits="WebAp plication2.WebF orm9" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>WebForm9 </title>
<meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
<meta content="C#" name="CODE_LANG UAGE">
<meta content="JavaSc ript" name="vs_defaul tClientScript">
<meta content="http://schemas.microso ft.com/intellisense/ie5"
name="vs_target Schema">
</HEAD>
<body MS_POSITIONING= "GridLayout ">
<form id="Form1" method="post" runat="server">
<asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px; POSITION:
absolute; TOP: 19px"
runat="server" Width="536px" Height="8px"></asp:Label>
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px; POSITION:
absolute; TOP: 152px"
runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
BorderStyle="No ne" BorderWidth="1p x"
BackColor="Whit e" CellPadding="4" >
<FooterStyle ForeColor="#003 399" BackColor="#99C CCC"></FooterStyle>
<SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
BackColor="#009 999"></SelectedItemSty le>
<ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
BackColor="#003 399"></HeaderStyle>
<PagerStyle HorizontalAlign ="Left" ForeColor="#003 399"
BackColor="#99C CCC" Mode="NumericPa ges"></PagerStyle>
</asp:DataGrid>
<asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px;
POSITION: absolute; TOP: 16px"
runat="server" Width="112px" Height="24px"
AutoPostBack="T rue"></asp:DropDownLis t>
<asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION:
absolute; TOP: 48px" runat="server"
Width="272px" Height="16px" ForeColor="Red" >I want to display notes of
selected employee</asp:Label>
<asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px; POSITION:
absolute; TOP: 72px"
runat="server" Width="704px" Height="56px"></asp:Label></form>
</body>
</HTML>
--------------------------------------------------code
behind--------------------------------------------------------------------------
using System;
using System.Collecti ons;
using System.Componen tModel;
using System.Data;
using System.Data.Sql Client;
using System.Drawing;
using System.Web;
using System.Web.Sess ionState;
using System.Web.UI;
using System.Web.UI.W ebControls;
using System.Web.UI.H tmlControls;
namespace WebApplication2
{
/// <summary>
/// Summary description for WebForm9.
/// </summary>
public class WebForm9 : System.Web.UI.P age
{
protected DataSet ds1 = new DataSet();
protected System.Web.UI.W ebControls.Labe l lblDisplay;
protected System.Web.UI.W ebControls.Data Grid DataGrid1;
protected System.Web.UI.W ebControls.Labe l lblText;
protected System.Web.UI.W ebControls.Labe l lblSpecific;
protected System.Web.UI.W ebControls.Drop DownList ddLastName;
private void Page_Load(objec t sender, System.EventArg s e)
{
if(!Page.IsPost Back)
{
string connectionStrin g = "data source =localhost; initial catalog
=Northwind; integrated security=true;" ;
SqlConnection sqlConnection1 = new SqlConnection(c onnectionString );
SqlCommand sqlCommand1 = new SqlCommand();
SqlDataAdapter sda1 = new SqlDataAdapter( );
// "dataset defined at class level"
// DataSet ds1 = new DataSet();
sda1.SelectComm and = sqlCommand1;
sda1.SelectComm and.Connection = sqlConnection1;
sda1.SelectComm and.CommandType = CommandType.Tex t;
sda1.SelectComm and.CommandText = "select * from Employees";
sda1.Fill(ds1," Employees");
SqlDataAdapter sda2 = new SqlDataAdapter( );
sda2.SelectComm and = sqlCommand1;
sda2.SelectComm and.Connection = sqlConnection1;
sda2.SelectComm and.CommandType = CommandType.Tex t;
sda2.SelectComm and.CommandText = "select * from Customers";
sda2.Fill(ds1," Customers");
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
// to fill with specific cell data
lblSpecific.Tex t = "Displaying specific Data:<br><br>";
lblSpecific.Tex t += ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
// to fill the datagrid
DataGrid1.DataS ource = ds1;
DataGrid1.DataM ember = "Employees" ;
DataGrid1.DataB ind();
}
}
#region Web Form Designer generated code
override protected void OnInit(EventArg s e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeCompo nent();
base.OnInit(e);
}
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeCompo nent()
{
this.ddLastName .SelectedIndexC hanged += new
System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
this.Load += new System.EventHan dler(this.Page_ Load);
}
#endregion
private void ddLastName_Sele ctedIndexChange d(object sender,
System.EventArg s e)
{
if(ddLastName.S electedIndex != 0)
{
int i = 0;
foreach(DataRow r in ds1.Tables["Employees"].Rows)
{
if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
{
lblDisplay.Text = ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
}
i++;
}
}
else
{
lblDisplay.Text = "";
}
}
}
} 12  1684 
The problem is that when you click the Dropdown Box, you trigger a postback.
Unfortunately, your Page_Load event only fills the dataset during the
initial GET. So there is no data to be had when you do your Autopostback.
Once a Webform is constructed and the page rendered, the object is
destroyed. You need to arrange for the data to be filled on the initial get
and saved to the cache for example.
cache("ds1)= Ds1
and as an else condition to your if not IsPostback
ds1 = cache("ds1")
page.DataBind() .. . . . .etc
PS: This is a common mistake to make.
HTH
"Bishoy George" <bi****@bishoy. com> wrote in message
news:uN******** ********@TK2MSF TNGP14.phx.gbl. .. I have a dataset called ds1 filled with 2 tables Employees and Customers
from Northwind database.
I have dropdownList called ddLastName with the following properties:
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
I have a label called lblDisplay
I want the label to display the Notes column data of the selected item in
the dropdownList.
My code is causing a NullReferenceEx ception.
Can anyone find out what is the problem please?
------------------------------------
Code: ----------------------------------------------------
<%@ Page language="c#" Codebehind="Web Form9.aspx.cs"
AutoEventWireup ="false" Inherits="WebAp plication2.WebF orm9" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>WebForm9 </title>
<meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
<meta content="C#" name="CODE_LANG UAGE">
<meta content="JavaSc ript" name="vs_defaul tClientScript">
<meta content="http://schemas.microso ft.com/intellisense/ie5"
name="vs_target Schema">
</HEAD>
<body MS_POSITIONING= "GridLayout ">
<form id="Form1" method="post" runat="server">
<asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px; POSITION:
absolute; TOP: 19px"
runat="server" Width="536px" Height="8px"></asp:Label>
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px; POSITION:
absolute; TOP: 152px"
runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
BorderStyle="No ne" BorderWidth="1p x"
BackColor="Whit e" CellPadding="4" >
<FooterStyle ForeColor="#003 399" BackColor="#99C CCC"></FooterStyle>
<SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
BackColor="#009 999"></SelectedItemSty le>
<ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
BackColor="#003 399"></HeaderStyle>
<PagerStyle HorizontalAlign ="Left" ForeColor="#003 399"
BackColor="#99C CCC" Mode="NumericPa ges"></PagerStyle>
</asp:DataGrid>
<asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px;
POSITION: absolute; TOP: 16px"
runat="server" Width="112px" Height="24px"
AutoPostBack="T rue"></asp:DropDownLis t>
<asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION:
absolute; TOP: 48px" runat="server"
Width="272px" Height="16px" ForeColor="Red" >I want to display notes of
selected employee</asp:Label>
<asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px; POSITION:
absolute; TOP: 72px"
runat="server" Width="704px" Height="56px"></asp:Label></form>
</body>
</HTML>
--------------------------------------------------code
behind--------------------------------------------------------------------------
using System;
using System.Collecti ons;
using System.Componen tModel;
using System.Data;
using System.Data.Sql Client;
using System.Drawing;
using System.Web;
using System.Web.Sess ionState;
using System.Web.UI;
using System.Web.UI.W ebControls;
using System.Web.UI.H tmlControls;
namespace WebApplication2
{
/// <summary>
/// Summary description for WebForm9.
/// </summary>
public class WebForm9 : System.Web.UI.P age
{
protected DataSet ds1 = new DataSet();
protected System.Web.UI.W ebControls.Labe l lblDisplay;
protected System.Web.UI.W ebControls.Data Grid DataGrid1;
protected System.Web.UI.W ebControls.Labe l lblText;
protected System.Web.UI.W ebControls.Labe l lblSpecific;
protected System.Web.UI.W ebControls.Drop DownList ddLastName;
private void Page_Load(objec t sender, System.EventArg s e)
{
if(!Page.IsPost Back)
{
string connectionStrin g = "data source =localhost; initial catalog
=Northwind; integrated security=true;" ;
SqlConnection sqlConnection1 = new SqlConnection(c onnectionString );
SqlCommand sqlCommand1 = new SqlCommand();
SqlDataAdapter sda1 = new SqlDataAdapter( );
// "dataset defined at class level"
// DataSet ds1 = new DataSet();
sda1.SelectComm and = sqlCommand1;
sda1.SelectComm and.Connection = sqlConnection1;
sda1.SelectComm and.CommandType = CommandType.Tex t;
sda1.SelectComm and.CommandText = "select * from Employees";
sda1.Fill(ds1," Employees");
SqlDataAdapter sda2 = new SqlDataAdapter( );
sda2.SelectComm and = sqlCommand1;
sda2.SelectComm and.Connection = sqlConnection1;
sda2.SelectComm and.CommandType = CommandType.Tex t;
sda2.SelectComm and.CommandText = "select * from Customers";
sda2.Fill(ds1," Customers");
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
// to fill with specific cell data
lblSpecific.Tex t = "Displaying specific Data:<br><br>";
lblSpecific.Tex t +=
ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
// to fill the datagrid
DataGrid1.DataS ource = ds1;
DataGrid1.DataM ember = "Employees" ;
DataGrid1.DataB ind();
}
}
#region Web Form Designer generated code
override protected void OnInit(EventArg s e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeCompo nent();
base.OnInit(e);
}
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeCompo nent()
{
this.ddLastName .SelectedIndexC hanged += new
System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
this.Load += new System.EventHan dler(this.Page_ Load);
}
#endregion
private void ddLastName_Sele ctedIndexChange d(object sender,
System.EventArg s e)
{
if(ddLastName.S electedIndex != 0)
{
int i = 0;
foreach(DataRow r in ds1.Tables["Employees"].Rows)
{
if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
{
lblDisplay.Text =
ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
}
i++;
}
}
else
{
lblDisplay.Text = "";
}
}
}
}
You are right. But, please write me more specific coding about caching:
1- code of caching exactly: as I looked at msdn there is difficult things to
set and there is no overloading of Cache.Add() that takes 1 parameter as you
wrote.
2- where exactly to put that caching code?
Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:uV******** ******@tk2msftn gp13.phx.gbl... The problem is that when you click the Dropdown Box, you trigger a
postback. Unfortunately, your Page_Load event only fills the dataset
during the initial GET. So there is no data to be had when you do your
Autopostback.
Once a Webform is constructed and the page rendered, the object is
destroyed. You need to arrange for the data to be filled on the initial
get and saved to the cache for example.
cache("ds1)= Ds1
and as an else condition to your if not IsPostback
ds1 = cache("ds1")
page.DataBind() .. . . . .etc
PS: This is a common mistake to make.
HTH
"Bishoy George" <bi****@bishoy. com> wrote in message
news:uN******** ********@TK2MSF TNGP14.phx.gbl. ..I have a dataset called ds1 filled with 2 tables Employees and Customers
from Northwind database.
I have dropdownList called ddLastName with the following properties:
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
I have a label called lblDisplay
I want the label to display the Notes column data of the selected item in
the dropdownList.
My code is causing a NullReferenceEx ception.
Can anyone find out what is the problem please?
------------------------------------
Code: ----------------------------------------------------
<%@ Page language="c#" Codebehind="Web Form9.aspx.cs"
AutoEventWireup ="false" Inherits="WebAp plication2.WebF orm9" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>WebForm9 </title>
<meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
<meta content="C#" name="CODE_LANG UAGE">
<meta content="JavaSc ript" name="vs_defaul tClientScript">
<meta content="http://schemas.microso ft.com/intellisense/ie5"
name="vs_target Schema">
</HEAD>
<body MS_POSITIONING= "GridLayout ">
<form id="Form1" method="post" runat="server">
<asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px; POSITION:
absolute; TOP: 19px"
runat="server" Width="536px" Height="8px"></asp:Label>
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px; POSITION:
absolute; TOP: 152px"
runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
BorderStyle="No ne" BorderWidth="1p x"
BackColor="Whit e" CellPadding="4" >
<FooterStyle ForeColor="#003 399" BackColor="#99C CCC"></FooterStyle>
<SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
BackColor="#009 999"></SelectedItemSty le>
<ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
BackColor="#003 399"></HeaderStyle>
<PagerStyle HorizontalAlign ="Left" ForeColor="#003 399"
BackColor="#99C CCC" Mode="NumericPa ges"></PagerStyle>
</asp:DataGrid>
<asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px;
POSITION: absolute; TOP: 16px"
runat="server" Width="112px" Height="24px"
AutoPostBack="T rue"></asp:DropDownLis t>
<asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION:
absolute; TOP: 48px" runat="server"
Width="272px" Height="16px" ForeColor="Red" >I want to display notes of
selected employee</asp:Label>
<asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px; POSITION:
absolute; TOP: 72px"
runat="server" Width="704px" Height="56px"></asp:Label></form>
</body>
</HTML>
--------------------------------------------------code
behind--------------------------------------------------------------------------
using System;
using System.Collecti ons;
using System.Componen tModel;
using System.Data;
using System.Data.Sql Client;
using System.Drawing;
using System.Web;
using System.Web.Sess ionState;
using System.Web.UI;
using System.Web.UI.W ebControls;
using System.Web.UI.H tmlControls;
namespace WebApplication2
{
/// <summary>
/// Summary description for WebForm9.
/// </summary>
public class WebForm9 : System.Web.UI.P age
{
protected DataSet ds1 = new DataSet();
protected System.Web.UI.W ebControls.Labe l lblDisplay;
protected System.Web.UI.W ebControls.Data Grid DataGrid1;
protected System.Web.UI.W ebControls.Labe l lblText;
protected System.Web.UI.W ebControls.Labe l lblSpecific;
protected System.Web.UI.W ebControls.Drop DownList ddLastName;
private void Page_Load(objec t sender, System.EventArg s e)
{
if(!Page.IsPost Back)
{
string connectionStrin g = "data source =localhost; initial catalog
=Northwind; integrated security=true;" ;
SqlConnection sqlConnection1 = new SqlConnection(c onnectionString );
SqlCommand sqlCommand1 = new SqlCommand();
SqlDataAdapter sda1 = new SqlDataAdapter( );
// "dataset defined at class level"
// DataSet ds1 = new DataSet();
sda1.SelectComm and = sqlCommand1;
sda1.SelectComm and.Connection = sqlConnection1;
sda1.SelectComm and.CommandType = CommandType.Tex t;
sda1.SelectComm and.CommandText = "select * from Employees";
sda1.Fill(ds1," Employees");
SqlDataAdapter sda2 = new SqlDataAdapter( );
sda2.SelectComm and = sqlCommand1;
sda2.SelectComm and.Connection = sqlConnection1;
sda2.SelectComm and.CommandType = CommandType.Tex t;
sda2.SelectComm and.CommandText = "select * from Customers";
sda2.Fill(ds1," Customers");
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
// to fill with specific cell data
lblSpecific.Tex t = "Displaying specific Data:<br><br>";
lblSpecific.Tex t +=
ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
// to fill the datagrid
DataGrid1.DataS ource = ds1;
DataGrid1.DataM ember = "Employees" ;
DataGrid1.DataB ind();
}
}
#region Web Form Designer generated code
override protected void OnInit(EventArg s e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeCompo nent();
base.OnInit(e);
}
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeCompo nent()
{
this.ddLastName .SelectedIndexC hanged += new
System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
this.Load += new System.EventHan dler(this.Page_ Load);
}
#endregion
private void ddLastName_Sele ctedIndexChange d(object sender,
System.EventArg s e)
{
if(ddLastName.S electedIndex != 0)
{
int i = 0;
foreach(DataRow r in ds1.Tables["Employees"].Rows)
{
if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
{
lblDisplay.Text =
ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
}
i++;
}
}
else
{
lblDisplay.Text = "";
}
}
}
}
Here's a little example which uses a helper function. And yes your right
about the constructor but that was not meant to be tested code just really
to point you in the right direction. In this example, the form is simply a
main switchboard which does not use any data, on the other forms in the
application they define the dataset, and adapter as class level variables
and load them from cache in the Page_Load event as described which can be
done with a simple assignment variableName=ca che("storedIden tifier").
Hope this helps you.
Regards - Mr N. . . .
----------------------
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
'Put user code to initialize the page here
If Not Page.IsPostBack Then
Me.adaptCalls.F ill(Me.DsCalls1 )
Me.adaptContact s.Fill(Me.DsCon tacts1)
Me.adaptContact Types.Fill(Me.D sContactTypes1)
AddToCache("ada ptCalls", adaptCalls)
AddToCache("ada ptContacts", adaptContacts)
AddToCache("ada ptContactTypes" , adaptContactTyp es)
AddToCache("dsC alls", DsCalls1)
AddToCache("dsC ontacts", DsContacts1)
AddToCache("dsC ontactTypes", DsContactTypes1 )
End If
End Sub
Private Sub AddToCache(ByVa l name As String, ByVal item As Object)
If Not IsNothing(Cache (name)) Then
Return
Else
Cache.Add(name, item, Nothing, DateTime.MaxVal ue,
System.TimeSpan .FromDays(20), Caching.CacheIt emPriority.Defa ult, Nothing)
End If
End Sub
"Bishoy George" <bi****@bishoy. com> wrote in message
news:ul******** ******@TK2MSFTN GP11.phx.gbl... You are right. But, please write me more specific coding about caching:
1- code of caching exactly: as I looked at msdn there is difficult things
to set and there is no overloading of Cache.Add() that takes 1 parameter
as you wrote.
2- where exactly to put that caching code?
Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:uV******** ******@tk2msftn gp13.phx.gbl... The problem is that when you click the Dropdown Box, you trigger a
postback. Unfortunately, your Page_Load event only fills the dataset
during the initial GET. So there is no data to be had when you do your
Autopostback.
Once a Webform is constructed and the page rendered, the object is
destroyed. You need to arrange for the data to be filled on the initial
get and saved to the cache for example.
cache("ds1)= Ds1
and as an else condition to your if not IsPostback
ds1 = cache("ds1")
page.DataBind() .. . . . .etc
PS: This is a common mistake to make.
HTH
"Bishoy George" <bi****@bishoy. com> wrote in message
news:uN******** ********@TK2MSF TNGP14.phx.gbl. ..I have a dataset called ds1 filled with 2 tables Employees and Customers
from Northwind database.
I have dropdownList called ddLastName with the following properties:
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
I have a label called lblDisplay
I want the label to display the Notes column data of the selected item
in the dropdownList.
My code is causing a NullReferenceEx ception.
Can anyone find out what is the problem please?
------------------------------------
Code: ----------------------------------------------------
<%@ Page language="c#" Codebehind="Web Form9.aspx.cs"
AutoEventWireup ="false" Inherits="WebAp plication2.WebF orm9" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>WebForm9 </title>
<meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
<meta content="C#" name="CODE_LANG UAGE">
<meta content="JavaSc ript" name="vs_defaul tClientScript">
<meta content="http://schemas.microso ft.com/intellisense/ie5"
name="vs_target Schema">
</HEAD>
<body MS_POSITIONING= "GridLayout ">
<form id="Form1" method="post" runat="server">
<asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px; POSITION:
absolute; TOP: 19px"
runat="server" Width="536px" Height="8px"></asp:Label>
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px;
POSITION: absolute; TOP: 152px"
runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
BorderStyle="No ne" BorderWidth="1p x"
BackColor="Whit e" CellPadding="4" >
<FooterStyle ForeColor="#003 399" BackColor="#99C CCC"></FooterStyle>
<SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
BackColor="#009 999"></SelectedItemSty le>
<ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
BackColor="#003 399"></HeaderStyle>
<PagerStyle HorizontalAlign ="Left" ForeColor="#003 399"
BackColor="#99C CCC" Mode="NumericPa ges"></PagerStyle>
</asp:DataGrid>
<asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px;
POSITION: absolute; TOP: 16px"
runat="server" Width="112px" Height="24px"
AutoPostBack="T rue"></asp:DropDownLis t>
<asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION:
absolute; TOP: 48px" runat="server"
Width="272px" Height="16px" ForeColor="Red" >I want to display notes
of selected employee</asp:Label>
<asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px; POSITION:
absolute; TOP: 72px"
runat="server" Width="704px" Height="56px"></asp:Label></form>
</body>
</HTML>
--------------------------------------------------code
behind--------------------------------------------------------------------------
using System;
using System.Collecti ons;
using System.Componen tModel;
using System.Data;
using System.Data.Sql Client;
using System.Drawing;
using System.Web;
using System.Web.Sess ionState;
using System.Web.UI;
using System.Web.UI.W ebControls;
using System.Web.UI.H tmlControls;
namespace WebApplication2
{
/// <summary>
/// Summary description for WebForm9.
/// </summary>
public class WebForm9 : System.Web.UI.P age
{
protected DataSet ds1 = new DataSet();
protected System.Web.UI.W ebControls.Labe l lblDisplay;
protected System.Web.UI.W ebControls.Data Grid DataGrid1;
protected System.Web.UI.W ebControls.Labe l lblText;
protected System.Web.UI.W ebControls.Labe l lblSpecific;
protected System.Web.UI.W ebControls.Drop DownList ddLastName;
private void Page_Load(objec t sender, System.EventArg s e)
{
if(!Page.IsPost Back)
{
string connectionStrin g = "data source =localhost; initial catalog
=Northwind; integrated security=true;" ;
SqlConnection sqlConnection1 = new SqlConnection(c onnectionString );
SqlCommand sqlCommand1 = new SqlCommand();
SqlDataAdapter sda1 = new SqlDataAdapter( );
// "dataset defined at class level"
// DataSet ds1 = new DataSet();
sda1.SelectComm and = sqlCommand1;
sda1.SelectComm and.Connection = sqlConnection1;
sda1.SelectComm and.CommandType = CommandType.Tex t;
sda1.SelectComm and.CommandText = "select * from Employees";
sda1.Fill(ds1," Employees");
SqlDataAdapter sda2 = new SqlDataAdapter( );
sda2.SelectComm and = sqlCommand1;
sda2.SelectComm and.Connection = sqlConnection1;
sda2.SelectComm and.CommandType = CommandType.Tex t;
sda2.SelectComm and.CommandText = "select * from Customers";
sda2.Fill(ds1," Customers");
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
// to fill with specific cell data
lblSpecific.Tex t = "Displaying specific Data:<br><br>";
lblSpecific.Tex t +=
ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
// to fill the datagrid
DataGrid1.DataS ource = ds1;
DataGrid1.DataM ember = "Employees" ;
DataGrid1.DataB ind();
}
}
#region Web Form Designer generated code
override protected void OnInit(EventArg s e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeCompo nent();
base.OnInit(e);
}
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeCompo nent()
{
this.ddLastName .SelectedIndexC hanged += new
System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
this.Load += new System.EventHan dler(this.Page_ Load);
}
#endregion
private void ddLastName_Sele ctedIndexChange d(object sender,
System.EventArg s e)
{
if(ddLastName.S electedIndex != 0)
{
int i = 0;
foreach(DataRow r in ds1.Tables["Employees"].Rows)
{
if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
{
lblDisplay.Text =
ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
}
i++;
}
}
else
{
lblDisplay.Text = "";
}
}
}
}
I am very disturbing, but if you please could you write it again in C#
because I don't understand vb.net.
Many Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:eH******** ******@TK2MSFTN GP14.phx.gbl... Here's a little example which uses a helper function. And yes your right
about the constructor but that was not meant to be tested code just really
to point you in the right direction. In this example, the form is simply a
main switchboard which does not use any data, on the other forms in the
application they define the dataset, and adapter as class level variables
and load them from cache in the Page_Load event as described which can be
done with a simple assignment variableName=ca che("storedIden tifier").
Hope this helps you.
Regards - Mr N. . . .
----------------------
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
'Put user code to initialize the page here
If Not Page.IsPostBack Then
Me.adaptCalls.F ill(Me.DsCalls1 )
Me.adaptContact s.Fill(Me.DsCon tacts1)
Me.adaptContact Types.Fill(Me.D sContactTypes1)
AddToCache("ada ptCalls", adaptCalls)
AddToCache("ada ptContacts", adaptContacts)
AddToCache("ada ptContactTypes" , adaptContactTyp es)
AddToCache("dsC alls", DsCalls1)
AddToCache("dsC ontacts", DsContacts1)
AddToCache("dsC ontactTypes", DsContactTypes1 )
End If
End Sub
Private Sub AddToCache(ByVa l name As String, ByVal item As Object)
If Not IsNothing(Cache (name)) Then
Return
Else
Cache.Add(name, item, Nothing, DateTime.MaxVal ue,
System.TimeSpan .FromDays(20), Caching.CacheIt emPriority.Defa ult, Nothing)
End If
End Sub
"Bishoy George" <bi****@bishoy. com> wrote in message
news:ul******** ******@TK2MSFTN GP11.phx.gbl... You are right. But, please write me more specific coding about caching:
1- code of caching exactly: as I looked at msdn there is difficult things
to set and there is no overloading of Cache.Add() that takes 1 parameter
as you wrote.
2- where exactly to put that caching code?
Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:uV******** ******@tk2msftn gp13.phx.gbl... The problem is that when you click the Dropdown Box, you trigger a
postback. Unfortunately, your Page_Load event only fills the dataset
during the initial GET. So there is no data to be had when you do your
Autopostback.
Once a Webform is constructed and the page rendered, the object is
destroyed. You need to arrange for the data to be filled on the initial
get and saved to the cache for example.
cache("ds1)= Ds1
and as an else condition to your if not IsPostback
ds1 = cache("ds1")
page.DataBind() .. . . . .etc
PS: This is a common mistake to make.
HTH
"Bishoy George" <bi****@bishoy. com> wrote in message
news:uN******** ********@TK2MSF TNGP14.phx.gbl. ..
I have a dataset called ds1 filled with 2 tables Employees and Customers
from Northwind database.
I have dropdownList called ddLastName with the following properties:
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
I have a label called lblDisplay
I want the label to display the Notes column data of the selected item
in the dropdownList.
My code is causing a NullReferenceEx ception.
Can anyone find out what is the problem please?
------------------------------------
Code: ----------------------------------------------------
<%@ Page language="c#" Codebehind="Web Form9.aspx.cs"
AutoEventWireup ="false" Inherits="WebAp plication2.WebF orm9" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>WebForm9 </title>
<meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
<meta content="C#" name="CODE_LANG UAGE">
<meta content="JavaSc ript" name="vs_defaul tClientScript">
<meta content="http://schemas.microso ft.com/intellisense/ie5"
name="vs_target Schema">
</HEAD>
<body MS_POSITIONING= "GridLayout ">
<form id="Form1" method="post" runat="server">
<asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px;
POSITION: absolute; TOP: 19px"
runat="server" Width="536px" Height="8px"></asp:Label>
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px;
POSITION: absolute; TOP: 152px"
runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
BorderStyle="No ne" BorderWidth="1p x"
BackColor="Whit e" CellPadding="4" >
<FooterStyle ForeColor="#003 399" BackColor="#99C CCC"></FooterStyle>
<SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
BackColor="#009 999"></SelectedItemSty le>
<ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
BackColor="#003 399"></HeaderStyle>
<PagerStyle HorizontalAlign ="Left" ForeColor="#003 399"
BackColor="#99C CCC" Mode="NumericPa ges"></PagerStyle>
</asp:DataGrid>
<asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px;
POSITION: absolute; TOP: 16px"
runat="server" Width="112px" Height="24px"
AutoPostBack="T rue"></asp:DropDownLis t>
<asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION:
absolute; TOP: 48px" runat="server"
Width="272px" Height="16px" ForeColor="Red" >I want to display notes
of selected employee</asp:Label>
<asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px;
POSITION: absolute; TOP: 72px"
runat="server" Width="704px" Height="56px"></asp:Label></form>
</body>
</HTML>
--------------------------------------------------code
behind--------------------------------------------------------------------------
using System;
using System.Collecti ons;
using System.Componen tModel;
using System.Data;
using System.Data.Sql Client;
using System.Drawing;
using System.Web;
using System.Web.Sess ionState;
using System.Web.UI;
using System.Web.UI.W ebControls;
using System.Web.UI.H tmlControls;
namespace WebApplication2
{
/// <summary>
/// Summary description for WebForm9.
/// </summary>
public class WebForm9 : System.Web.UI.P age
{
protected DataSet ds1 = new DataSet();
protected System.Web.UI.W ebControls.Labe l lblDisplay;
protected System.Web.UI.W ebControls.Data Grid DataGrid1;
protected System.Web.UI.W ebControls.Labe l lblText;
protected System.Web.UI.W ebControls.Labe l lblSpecific;
protected System.Web.UI.W ebControls.Drop DownList ddLastName;
private void Page_Load(objec t sender, System.EventArg s e)
{
if(!Page.IsPost Back)
{
string connectionStrin g = "data source =localhost; initial catalog
=Northwind; integrated security=true;" ;
SqlConnection sqlConnection1 = new SqlConnection(c onnectionString );
SqlCommand sqlCommand1 = new SqlCommand();
SqlDataAdapter sda1 = new SqlDataAdapter( );
// "dataset defined at class level"
// DataSet ds1 = new DataSet();
sda1.SelectComm and = sqlCommand1;
sda1.SelectComm and.Connection = sqlConnection1;
sda1.SelectComm and.CommandType = CommandType.Tex t;
sda1.SelectComm and.CommandText = "select * from Employees";
sda1.Fill(ds1," Employees");
SqlDataAdapter sda2 = new SqlDataAdapter( );
sda2.SelectComm and = sqlCommand1;
sda2.SelectComm and.Connection = sqlConnection1;
sda2.SelectComm and.CommandType = CommandType.Tex t;
sda2.SelectComm and.CommandText = "select * from Customers";
sda2.Fill(ds1," Customers");
ddLastName.Data Source = ds1;
ddLastName.Data Member = "Employees" ;
ddLastName.Data TextField = "LastName";
ddLastName.Data Bind();
ddLastName.Item s.Insert(0,"Sel ect:");
// to fill with specific cell data
lblSpecific.Tex t = "Displaying specific Data:<br><br>";
lblSpecific.Tex t +=
ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
// to fill the datagrid
DataGrid1.DataS ource = ds1;
DataGrid1.DataM ember = "Employees" ;
DataGrid1.DataB ind();
}
}
#region Web Form Designer generated code
override protected void OnInit(EventArg s e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeCompo nent();
base.OnInit(e);
}
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeCompo nent()
{
this.ddLastName .SelectedIndexC hanged += new
System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
this.Load += new System.EventHan dler(this.Page_ Load);
}
#endregion
private void ddLastName_Sele ctedIndexChange d(object sender,
System.EventArg s e)
{
if(ddLastName.S electedIndex != 0)
{
int i = 0;
foreach(DataRow r in ds1.Tables["Employees"].Rows)
{
if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
{
lblDisplay.Text =
ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
}
i++;
}
}
else
{
lblDisplay.Text = "";
}
}
}
}
I could, but you hould do some research yourself. This is not rocket science
(only a few simple lines) and there are translators out on the web which
will do this for you if you look.
I don't mean to be tough on you, but you do need to get hold of the
pioneering spirit in order to progress. Twenty years ago, I was working in
an electronics lab fixing some equipment and I was having trouble with one
particular circuit. I asked my boss for help, and his reply was to slap down
hard the manual on my desk and he told me to read it. I was furious at him
and decided never to ask him for help again and then subsequently became an
expert on this particular equipment.
I think his approach was perhaps a bit draconian, however, it made me more
self sufficient than I perhaps would have been had everything been done for
me.
Regards - Mr N . . . .
"Bishoy George" <bi****@bishoy. com> wrote in message
news:eR******** ******@TK2MSFTN GP09.phx.gbl... I am very disturbing, but if you please could you write it again in C#
because I don't understand vb.net.
Many Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:eH******** ******@TK2MSFTN GP14.phx.gbl... Here's a little example which uses a helper function. And yes your right
about the constructor but that was not meant to be tested code just
really to point you in the right direction. In this example, the form is
simply a main switchboard which does not use any data, on the other forms
in the application they define the dataset, and adapter as class level
variables and load them from cache in the Page_Load event as described
which can be done with a simple assignment
variableName=ca che("storedIden tifier").
Hope this helps you.
Regards - Mr N. . . .
----------------------
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
'Put user code to initialize the page here
If Not Page.IsPostBack Then
Me.adaptCalls.F ill(Me.DsCalls1 )
Me.adaptContact s.Fill(Me.DsCon tacts1)
Me.adaptContact Types.Fill(Me.D sContactTypes1)
AddToCache("ada ptCalls", adaptCalls)
AddToCache("ada ptContacts", adaptContacts)
AddToCache("ada ptContactTypes" , adaptContactTyp es)
AddToCache("dsC alls", DsCalls1)
AddToCache("dsC ontacts", DsContacts1)
AddToCache("dsC ontactTypes", DsContactTypes1 )
End If
End Sub
Private Sub AddToCache(ByVa l name As String, ByVal item As Object)
If Not IsNothing(Cache (name)) Then
Return
Else
Cache.Add(name, item, Nothing, DateTime.MaxVal ue,
System.TimeSpan .FromDays(20), Caching.CacheIt emPriority.Defa ult, Nothing)
End If
End Sub
"Bishoy George" <bi****@bishoy. com> wrote in message
news:ul******** ******@TK2MSFTN GP11.phx.gbl... You are right. But, please write me more specific coding about caching:
1- code of caching exactly: as I looked at msdn there is difficult
things to set and there is no overloading of Cache.Add() that takes 1
parameter as you wrote.
2- where exactly to put that caching code?
Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:uV******** ******@tk2msftn gp13.phx.gbl...
The problem is that when you click the Dropdown Box, you trigger a
postback. Unfortunately, your Page_Load event only fills the dataset
during the initial GET. So there is no data to be had when you do your
Autopostback.
Once a Webform is constructed and the page rendered, the object is
destroyed. You need to arrange for the data to be filled on the initial
get and saved to the cache for example.
cache("ds1)= Ds1
and as an else condition to your if not IsPostback
ds1 = cache("ds1")
page.DataBind() .. . . . .etc
PS: This is a common mistake to make.
HTH
"Bishoy George" <bi****@bishoy. com> wrote in message
news:uN******** ********@TK2MSF TNGP14.phx.gbl. ..
>I have a dataset called ds1 filled with 2 tables Employees and
>Customer s from Northwind database.
> I have dropdownList called ddLastName with the following properties:
>
> ddLastName.Data Source = ds1;
> ddLastName.Data Member = "Employees" ;
> ddLastName.Data TextField = "LastName";
> ddLastName.Data Bind();
> ddLastName.Item s.Insert(0,"Sel ect:");
>
> I have a label called lblDisplay
>
> I want the label to display the Notes column data of the selected item
> in the dropdownList.
>
> My code is causing a NullReferenceEx ception.
> Can anyone find out what is the problem please?
>
> ------------------------------------
> Code: ----------------------------------------------------
> <%@ Page language="c#" Codebehind="Web Form9.aspx.cs"
> AutoEventWireup ="false" Inherits="WebAp plication2.WebF orm9" %>
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
> <HTML>
> <HEAD>
> <title>WebForm9 </title>
> <meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
> <meta content="C#" name="CODE_LANG UAGE">
> <meta content="JavaSc ript" name="vs_defaul tClientScript">
> <meta content="http://schemas.microso ft.com/intellisense/ie5"
> name="vs_target Schema">
> </HEAD>
> <body MS_POSITIONING= "GridLayout ">
> <form id="Form1" method="post" runat="server">
> <asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px;
> POSITION: absolute; TOP: 19px"
> runat="server" Width="536px" Height="8px"></asp:Label>
> <asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px;
> POSITION: absolute; TOP: 152px"
> runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
> BorderStyle="No ne" BorderWidth="1p x"
> BackColor="Whit e" CellPadding="4" >
> <FooterStyle ForeColor="#003 399" BackColor="#99C CCC"></FooterStyle>
> <SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
> BackColor="#009 999"></SelectedItemSty le>
> <ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
> <HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
> BackColor="#003 399"></HeaderStyle>
> <PagerStyle HorizontalAlign ="Left" ForeColor="#003 399"
> BackColor="#99C CCC" Mode="NumericPa ges"></PagerStyle>
> </asp:DataGrid>
> <asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px;
> POSITION: absolute; TOP: 16px"
> runat="server" Width="112px" Height="24px"
> AutoPostBack="T rue"></asp:DropDownLis t>
> <asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION:
> absolute; TOP: 48px" runat="server"
> Width="272px" Height="16px" ForeColor="Red" >I want to display notes
> of selected employee</asp:Label>
> <asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px;
> POSITION: absolute; TOP: 72px"
> runat="server" Width="704px" Height="56px"></asp:Label></form>
> </body>
> </HTML>
>
> --------------------------------------------------code
> behind--------------------------------------------------------------------------
> using System;
> using System.Collecti ons;
> using System.Componen tModel;
> using System.Data;
> using System.Data.Sql Client;
> using System.Drawing;
> using System.Web;
> using System.Web.Sess ionState;
> using System.Web.UI;
> using System.Web.UI.W ebControls;
> using System.Web.UI.H tmlControls;
>
> namespace WebApplication2
> {
> /// <summary>
> /// Summary description for WebForm9.
> /// </summary>
> public class WebForm9 : System.Web.UI.P age
> {
> protected DataSet ds1 = new DataSet();
> protected System.Web.UI.W ebControls.Labe l lblDisplay;
> protected System.Web.UI.W ebControls.Data Grid DataGrid1;
> protected System.Web.UI.W ebControls.Labe l lblText;
> protected System.Web.UI.W ebControls.Labe l lblSpecific;
> protected System.Web.UI.W ebControls.Drop DownList ddLastName;
>
> private void Page_Load(objec t sender, System.EventArg s e)
> {
> if(!Page.IsPost Back)
> {
> string connectionStrin g = "data source =localhost; initial catalog
> =Northwind; integrated security=true;" ;
> SqlConnection sqlConnection1 = new SqlConnection(c onnectionString );
>
> SqlCommand sqlCommand1 = new SqlCommand();
> SqlDataAdapter sda1 = new SqlDataAdapter( );
>
> // "dataset defined at class level"
> // DataSet ds1 = new DataSet();
>
> sda1.SelectComm and = sqlCommand1;
> sda1.SelectComm and.Connection = sqlConnection1;
> sda1.SelectComm and.CommandType = CommandType.Tex t;
> sda1.SelectComm and.CommandText = "select * from Employees";
>
> sda1.Fill(ds1," Employees");
>
> SqlDataAdapter sda2 = new SqlDataAdapter( );
>
> sda2.SelectComm and = sqlCommand1;
> sda2.SelectComm and.Connection = sqlConnection1;
> sda2.SelectComm and.CommandType = CommandType.Tex t;
> sda2.SelectComm and.CommandText = "select * from Customers";
>
> sda2.Fill(ds1," Customers");
>
> ddLastName.Data Source = ds1;
> ddLastName.Data Member = "Employees" ;
> ddLastName.Data TextField = "LastName";
> ddLastName.Data Bind();
> ddLastName.Item s.Insert(0,"Sel ect:");
>
> // to fill with specific cell data
> lblSpecific.Tex t = "Displaying specific Data:<br><br>";
> lblSpecific.Tex t +=
> ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
>
> // to fill the datagrid
> DataGrid1.DataS ource = ds1;
> DataGrid1.DataM ember = "Employees" ;
> DataGrid1.DataB ind();
>
> }
> }
>
> #region Web Form Designer generated code
> override protected void OnInit(EventArg s e)
> {
> //
> // CODEGEN: This call is required by the ASP.NET Web Form Designer.
> //
> InitializeCompo nent();
> base.OnInit(e);
> }
>
> /// <summary>
> /// Required method for Designer support - do not modify
> /// the contents of this method with the code editor.
> /// </summary>
> private void InitializeCompo nent()
> {
> this.ddLastName .SelectedIndexC hanged += new
> System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
> this.Load += new System.EventHan dler(this.Page_ Load);
>
> }
> #endregion
>
> private void ddLastName_Sele ctedIndexChange d(object sender,
> System.EventArg s e)
> {
> if(ddLastName.S electedIndex != 0)
> {
> int i = 0;
> foreach(DataRow r in ds1.Tables["Employees"].Rows)
> {
> if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
> {
> lblDisplay.Text =
> ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
> }
> i++;
> }
> }
> else
> {
> lblDisplay.Text = "";
> }
> }
> }
> }
>
Why don't you use an online conversion utility ? http://www.developerfusion.co.uk/uti...btocsharp.aspx
will convert VB.NET to C# ( and C# to VB.NET ) for you.
Juan T. Llibre, ASP.NET MVP
ASP.NET FAQ : http://asp.net.do/faq/
Foros de ASP.NET en Español : http://asp.net.do/foros/
=============== =============== ========
"Bishoy George" <bi****@bishoy. com> wrote in message
news:eR******** ******@TK2MSFTN GP09.phx.gbl... I am very disturbing, but if you please could you write it again in C# because I don't
understand vb.net.
Many Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:eH******** ******@TK2MSFTN GP14.phx.gbl... Here's a little example which uses a helper function. And yes your right about the
constructor but that was not meant to be tested code just really to point you in the
right direction. In this example, the form is simply a main switchboard which does not
use any data, on the other forms in the application they define the dataset, and
adapter as class level variables and load them from cache in the Page_Load event as
described which can be done with a simple assignment
variableName=ca che("storedIden tifier").
Hope this helps you.
Regards - Mr N. . . .
----------------------
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArg s)
Handles MyBase.Load
'Put user code to initialize the page here
If Not Page.IsPostBack Then
Me.adaptCalls.F ill(Me.DsCalls1 )
Me.adaptContact s.Fill(Me.DsCon tacts1)
Me.adaptContact Types.Fill(Me.D sContactTypes1)
AddToCache("ada ptCalls", adaptCalls)
AddToCache("ada ptContacts", adaptContacts)
AddToCache("ada ptContactTypes" , adaptContactTyp es)
AddToCache("dsC alls", DsCalls1)
AddToCache("dsC ontacts", DsContacts1)
AddToCache("dsC ontactTypes", DsContactTypes1 )
End If
End Sub
Private Sub AddToCache(ByVa l name As String, ByVal item As Object)
If Not IsNothing(Cache (name)) Then
Return
Else
Cache.Add(name, item, Nothing, DateTime.MaxVal ue,
System.TimeSpan .FromDays(20), Caching.CacheIt emPriority.Defa ult, Nothing)
End If
End Sub
"Bishoy George" <bi****@bishoy. com> wrote in message
news:ul******** ******@TK2MSFTN GP11.phx.gbl... You are right. But, please write me more specific coding about caching:
1- code of caching exactly: as I looked at msdn there is difficult things to set and
there is no overloading of Cache.Add() that takes 1 parameter as you wrote.
2- where exactly to put that caching code?
Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:uV******** ******@tk2msftn gp13.phx.gbl...
The problem is that when you click the Dropdown Box, you trigger a postback.
Unfortunately, your Page_Load event only fills the dataset during the initial GET. So
there is no data to be had when you do your Autopostback.
Once a Webform is constructed and the page rendered, the object is destroyed. You
need to arrange for the data to be filled on the initial get and saved to the cache
for example.
cache("ds1)= Ds1
and as an else condition to your if not IsPostback
ds1 = cache("ds1")
page.DataBind() .. . . . .etc
PS: This is a common mistake to make.
HTH
"Bishoy George" <bi****@bishoy. com> wrote in message
news:uN******** ********@TK2MSF TNGP14.phx.gbl. ..
>I have a dataset called ds1 filled with 2 tables Employees and Customers from
>Northwin d database.
> I have dropdownList called ddLastName with the following properties:
>
> ddLastName.Data Source = ds1;
> ddLastName.Data Member = "Employees" ;
> ddLastName.Data TextField = "LastName";
> ddLastName.Data Bind();
> ddLastName.Item s.Insert(0,"Sel ect:");
>
> I have a label called lblDisplay
>
> I want the label to display the Notes column data of the selected item in the
> dropdownList.
>
> My code is causing a NullReferenceEx ception.
> Can anyone find out what is the problem please?
>
> ------------------------------------
> Code: ----------------------------------------------------
> <%@ Page language="c#" Codebehind="Web Form9.aspx.cs" AutoEventWireup ="false"
> Inherits="WebAp plication2.WebF orm9" %>
> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
> <HTML>
> <HEAD>
> <title>WebForm9 </title>
> <meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
> <meta content="C#" name="CODE_LANG UAGE">
> <meta content="JavaSc ript" name="vs_defaul tClientScript">
> <meta content="http://schemas.microso ft.com/intellisense/ie5"
> name="vs_target Schema">
> </HEAD>
> <body MS_POSITIONING= "GridLayout ">
> <form id="Form1" method="post" runat="server">
> <asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px; POSITION: absolute;
> TOP: 19px"
> runat="server" Width="536px" Height="8px"></asp:Label>
> <asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px; POSITION: absolute;
> TOP: 152px"
> runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
> BorderStyle="No ne" BorderWidth="1p x"
> BackColor="Whit e" CellPadding="4" >
> <FooterStyle ForeColor="#003 399" BackColor="#99C CCC"></FooterStyle>
> <SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
> BackColor="#009 999"></SelectedItemSty le>
> <ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
> <HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
> BackColor="#003 399"></HeaderStyle>
> <PagerStyle HorizontalAlign ="Left" ForeColor="#003 399" BackColor="#99C CCC"
> Mode="NumericPa ges"></PagerStyle>
> </asp:DataGrid>
> <asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px; POSITION:
> absolute; TOP: 16px"
> runat="server" Width="112px" Height="24px"
> AutoPostBack="T rue"></asp:DropDownLis t>
> <asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION: absolute; TOP:
> 48px" runat="server"
> Width="272px" Height="16px" ForeColor="Red" >I want to display notes of selected
> employee</asp:Label>
> <asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px; POSITION: absolute;
> TOP: 72px"
> runat="server" Width="704px" Height="56px"></asp:Label></form>
> </body>
> </HTML>
>
> --------------------------------------------------code
> behind--------------------------------------------------------------------------
> using System;
> using System.Collecti ons;
> using System.Componen tModel;
> using System.Data;
> using System.Data.Sql Client;
> using System.Drawing;
> using System.Web;
> using System.Web.Sess ionState;
> using System.Web.UI;
> using System.Web.UI.W ebControls;
> using System.Web.UI.H tmlControls;
>
> namespace WebApplication2
> {
> /// <summary>
> /// Summary description for WebForm9.
> /// </summary>
> public class WebForm9 : System.Web.UI.P age
> {
> protected DataSet ds1 = new DataSet();
> protected System.Web.UI.W ebControls.Labe l lblDisplay;
> protected System.Web.UI.W ebControls.Data Grid DataGrid1;
> protected System.Web.UI.W ebControls.Labe l lblText;
> protected System.Web.UI.W ebControls.Labe l lblSpecific;
> protected System.Web.UI.W ebControls.Drop DownList ddLastName;
>
> private void Page_Load(objec t sender, System.EventArg s e)
> {
> if(!Page.IsPost Back)
> {
> string connectionStrin g = "data source =localhost; initial catalog =Northwind;
> integrated security=true;" ;
> SqlConnection sqlConnection1 = new SqlConnection(c onnectionString );
>
> SqlCommand sqlCommand1 = new SqlCommand();
> SqlDataAdapter sda1 = new SqlDataAdapter( );
>
> // "dataset defined at class level"
> // DataSet ds1 = new DataSet();
>
> sda1.SelectComm and = sqlCommand1;
> sda1.SelectComm and.Connection = sqlConnection1;
> sda1.SelectComm and.CommandType = CommandType.Tex t;
> sda1.SelectComm and.CommandText = "select * from Employees";
>
> sda1.Fill(ds1," Employees");
>
> SqlDataAdapter sda2 = new SqlDataAdapter( );
>
> sda2.SelectComm and = sqlCommand1;
> sda2.SelectComm and.Connection = sqlConnection1;
> sda2.SelectComm and.CommandType = CommandType.Tex t;
> sda2.SelectComm and.CommandText = "select * from Customers";
>
> sda2.Fill(ds1," Customers");
>
> ddLastName.Data Source = ds1;
> ddLastName.Data Member = "Employees" ;
> ddLastName.Data TextField = "LastName";
> ddLastName.Data Bind();
> ddLastName.Item s.Insert(0,"Sel ect:");
>
> // to fill with specific cell data
> lblSpecific.Tex t = "Displaying specific Data:<br><br>";
> lblSpecific.Tex t += ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
>
> // to fill the datagrid
> DataGrid1.DataS ource = ds1;
> DataGrid1.DataM ember = "Employees" ;
> DataGrid1.DataB ind();
>
> }
> }
>
> #region Web Form Designer generated code
> override protected void OnInit(EventArg s e)
> {
> //
> // CODEGEN: This call is required by the ASP.NET Web Form Designer.
> //
> InitializeCompo nent();
> base.OnInit(e);
> }
>
> /// <summary>
> /// Required method for Designer support - do not modify
> /// the contents of this method with the code editor.
> /// </summary>
> private void InitializeCompo nent()
> {
> this.ddLastName .SelectedIndexC hanged += new
> System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
> this.Load += new System.EventHan dler(this.Page_ Load);
>
> }
> #endregion
>
> private void ddLastName_Sele ctedIndexChange d(object sender, System.EventArg s e)
> {
> if(ddLastName.S electedIndex != 0)
> {
> int i = 0;
> foreach(DataRow r in ds1.Tables["Employees"].Rows)
> {
> if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
> {
> lblDisplay.Text = ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
> }
> i++;
> }
> }
> else
> {
> lblDisplay.Text = "";
> }
> }
> }
> }
>
Many thanks Juan for this utility for conversion.
Mr.Newbie:
your code has errors so I can't understand it or even convert it. Still,
thank you.
"Juan T. Llibre" <no***********@ nowhere.com> wrote in message
news:ek******** ******@TK2MSFTN GP14.phx.gbl... Why don't you use an online conversion utility ?
http://www.developerfusion.co.uk/uti...btocsharp.aspx
will convert VB.NET to C# ( and C# to VB.NET ) for you.
Juan T. Llibre, ASP.NET MVP
ASP.NET FAQ : http://asp.net.do/faq/
Foros de ASP.NET en Español : http://asp.net.do/foros/
=============== =============== ========
"Bishoy George" <bi****@bishoy. com> wrote in message
news:eR******** ******@TK2MSFTN GP09.phx.gbl...I am very disturbing, but if you please could you write it again in C#
because I don't understand vb.net.
Many Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:eH******** ******@TK2MSFTN GP14.phx.gbl... Here's a little example which uses a helper function. And yes your right
about the constructor but that was not meant to be tested code just
really to point you in the right direction. In this example, the form is
simply a main switchboard which does not use any data, on the other
forms in the application they define the dataset, and adapter as class
level variables and load them from cache in the Page_Load event as
described which can be done with a simple assignment
variableName=ca che("storedIden tifier").
Hope this helps you.
Regards - Mr N. . . .
----------------------
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
'Put user code to initialize the page here
If Not Page.IsPostBack Then
Me.adaptCalls.F ill(Me.DsCalls1 )
Me.adaptContact s.Fill(Me.DsCon tacts1)
Me.adaptContact Types.Fill(Me.D sContactTypes1)
AddToCache("ada ptCalls", adaptCalls)
AddToCache("ada ptContacts", adaptContacts)
AddToCache("ada ptContactTypes" , adaptContactTyp es)
AddToCache("dsC alls", DsCalls1)
AddToCache("dsC ontacts", DsContacts1)
AddToCache("dsC ontactTypes", DsContactTypes1 )
End If
End Sub
Private Sub AddToCache(ByVa l name As String, ByVal item As Object)
If Not IsNothing(Cache (name)) Then
Return
Else
Cache.Add(name, item, Nothing, DateTime.MaxVal ue,
System.TimeSpan .FromDays(20), Caching.CacheIt emPriority.Defa ult,
Nothing)
End If
End Sub
"Bishoy George" <bi****@bishoy. com> wrote in message
news:ul******** ******@TK2MSFTN GP11.phx.gbl...
You are right. But, please write me more specific coding about caching:
1- code of caching exactly: as I looked at msdn there is difficult
things to set and there is no overloading of Cache.Add() that takes 1
parameter as you wrote.
2- where exactly to put that caching code?
Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:uV******** ******@tk2msftn gp13.phx.gbl...
> The problem is that when you click the Dropdown Box, you trigger a
> postback. Unfortunately, your Page_Load event only fills the dataset
> during the initial GET. So there is no data to be had when you do your
> Autopostback.
>
> Once a Webform is constructed and the page rendered, the object is
> destroyed. You need to arrange for the data to be filled on the
> initial get and saved to the cache for example.
>
> cache("ds1)= Ds1
>
>
> and as an else condition to your if not IsPostback
>
> ds1 = cache("ds1")
>
> page.DataBind() .. . . . .etc
>
> PS: This is a common mistake to make.
>
> HTH
>
>
>
> "Bishoy George" <bi****@bishoy. com> wrote in message
> news:uN******** ********@TK2MSF TNGP14.phx.gbl. ..
>>I have a dataset called ds1 filled with 2 tables Employees and
>>Custome rs from Northwind database.
>> I have dropdownList called ddLastName with the following properties:
>>
>> ddLastName.Data Source = ds1;
>> ddLastName.Data Member = "Employees" ;
>> ddLastName.Data TextField = "LastName";
>> ddLastName.Data Bind();
>> ddLastName.Item s.Insert(0,"Sel ect:");
>>
>> I have a label called lblDisplay
>>
>> I want the label to display the Notes column data of the selected
>> item in the dropdownList.
>>
>> My code is causing a NullReferenceEx ception.
>> Can anyone find out what is the problem please?
>>
>> ------------------------------------
>> Code: ----------------------------------------------------
>> <%@ Page language="c#" Codebehind="Web Form9.aspx.cs"
>> AutoEventWireup ="false" Inherits="WebAp plication2.WebF orm9" %>
>> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
>> <HTML>
>> <HEAD>
>> <title>WebForm9 </title>
>> <meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
>> <meta content="C#" name="CODE_LANG UAGE">
>> <meta content="JavaSc ript" name="vs_defaul tClientScript">
>> <meta content="http://schemas.microso ft.com/intellisense/ie5"
>> name="vs_target Schema">
>> </HEAD>
>> <body MS_POSITIONING= "GridLayout ">
>> <form id="Form1" method="post" runat="server">
>> <asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px;
>> POSITION: absolute; TOP: 19px"
>> runat="server" Width="536px" Height="8px"></asp:Label>
>> <asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px;
>> POSITION: absolute; TOP: 152px"
>> runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
>> BorderStyle="No ne" BorderWidth="1p x"
>> BackColor="Whit e" CellPadding="4" >
>> <FooterStyle ForeColor="#003 399"
>> BackColor="#99C CCC"></FooterStyle>
>> <SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
>> BackColor="#009 999"></SelectedItemSty le>
>> <ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
>> <HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
>> BackColor="#003 399"></HeaderStyle>
>> <PagerStyle HorizontalAlign ="Left" ForeColor="#003 399"
>> BackColor="#99C CCC" Mode="NumericPa ges"></PagerStyle>
>> </asp:DataGrid>
>> <asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px;
>> POSITION: absolute; TOP: 16px"
>> runat="server" Width="112px" Height="24px"
>> AutoPostBack="T rue"></asp:DropDownLis t>
>> <asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION:
>> absolute; TOP: 48px" runat="server"
>> Width="272px" Height="16px" ForeColor="Red" >I want to display
>> notes of selected employee</asp:Label>
>> <asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px;
>> POSITION: absolute; TOP: 72px"
>> runat="server" Width="704px" Height="56px"></asp:Label></form>
>> </body>
>> </HTML>
>>
>> --------------------------------------------------code
>> behind--------------------------------------------------------------------------
>> using System;
>> using System.Collecti ons;
>> using System.Componen tModel;
>> using System.Data;
>> using System.Data.Sql Client;
>> using System.Drawing;
>> using System.Web;
>> using System.Web.Sess ionState;
>> using System.Web.UI;
>> using System.Web.UI.W ebControls;
>> using System.Web.UI.H tmlControls;
>>
>> namespace WebApplication2
>> {
>> /// <summary>
>> /// Summary description for WebForm9.
>> /// </summary>
>> public class WebForm9 : System.Web.UI.P age
>> {
>> protected DataSet ds1 = new DataSet();
>> protected System.Web.UI.W ebControls.Labe l lblDisplay;
>> protected System.Web.UI.W ebControls.Data Grid DataGrid1;
>> protected System.Web.UI.W ebControls.Labe l lblText;
>> protected System.Web.UI.W ebControls.Labe l lblSpecific;
>> protected System.Web.UI.W ebControls.Drop DownList ddLastName;
>>
>> private void Page_Load(objec t sender, System.EventArg s e)
>> {
>> if(!Page.IsPost Back)
>> {
>> string connectionStrin g = "data source =localhost; initial catalog
>> =Northwind; integrated security=true;" ;
>> SqlConnection sqlConnection1 = new
>> SqlConnection(c onnectionString );
>>
>> SqlCommand sqlCommand1 = new SqlCommand();
>> SqlDataAdapter sda1 = new SqlDataAdapter( );
>>
>> // "dataset defined at class level"
>> // DataSet ds1 = new DataSet();
>>
>> sda1.SelectComm and = sqlCommand1;
>> sda1.SelectComm and.Connection = sqlConnection1;
>> sda1.SelectComm and.CommandType = CommandType.Tex t;
>> sda1.SelectComm and.CommandText = "select * from Employees";
>>
>> sda1.Fill(ds1," Employees");
>>
>> SqlDataAdapter sda2 = new SqlDataAdapter( );
>>
>> sda2.SelectComm and = sqlCommand1;
>> sda2.SelectComm and.Connection = sqlConnection1;
>> sda2.SelectComm and.CommandType = CommandType.Tex t;
>> sda2.SelectComm and.CommandText = "select * from Customers";
>>
>> sda2.Fill(ds1," Customers");
>>
>> ddLastName.Data Source = ds1;
>> ddLastName.Data Member = "Employees" ;
>> ddLastName.Data TextField = "LastName";
>> ddLastName.Data Bind();
>> ddLastName.Item s.Insert(0,"Sel ect:");
>>
>> // to fill with specific cell data
>> lblSpecific.Tex t = "Displaying specific Data:<br><br>";
>> lblSpecific.Tex t +=
>> ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
>>
>> // to fill the datagrid
>> DataGrid1.DataS ource = ds1;
>> DataGrid1.DataM ember = "Employees" ;
>> DataGrid1.DataB ind();
>>
>> }
>> }
>>
>> #region Web Form Designer generated code
>> override protected void OnInit(EventArg s e)
>> {
>> //
>> // CODEGEN: This call is required by the ASP.NET Web Form Designer.
>> //
>> InitializeCompo nent();
>> base.OnInit(e);
>> }
>>
>> /// <summary>
>> /// Required method for Designer support - do not modify
>> /// the contents of this method with the code editor.
>> /// </summary>
>> private void InitializeCompo nent()
>> {
>> this.ddLastName .SelectedIndexC hanged += new
>> System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
>> this.Load += new System.EventHan dler(this.Page_ Load);
>>
>> }
>> #endregion
>>
>> private void ddLastName_Sele ctedIndexChange d(object sender,
>> System.EventArg s e)
>> {
>> if(ddLastName.S electedIndex != 0)
>> {
>> int i = 0;
>> foreach(DataRow r in ds1.Tables["Employees"].Rows)
>> {
>> if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
>> {
>> lblDisplay.Text =
>> ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
>> }
>> i++;
>> }
>> }
>> else
>> {
>> lblDisplay.Text = "";
>> }
>> }
>> }
>> }
>>
>
>
re: Many thanks Juan for this utility for conversion.
You're very welcome.
re: Mr.Newbie:
your code has errors
Actually, it doesn't.
You have to work around the limitations of the conversion tool,
by making sure you insert code-line breaks ( the underscore in VB.NET )
so that the conversion utility doesn't think the code statements are truncated.
So, if you insert underscores at the end of the longest lines,
the conversion tool can understand them.
For example, here's an appropiately marked source segment :
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As _
System.EventArg s) Handles MyBase.Load
'Put user code to initialize the page here
If Not Page.IsPostBack Then
Me.adaptCalls.F ill(Me.DsCalls1 )
Me.adaptContact s.Fill(Me.DsCon tacts1)
Me.adaptContact Types.Fill(Me.D sContactTypes1)
AddToCache("ada ptCalls", adaptCalls)
AddToCache("ada ptContacts", adaptContacts)
AddToCache("ada ptContactTypes" , adaptContactTyp es)
AddToCache("dsC alls", DsCalls1)
AddToCache("dsC ontacts", DsContacts1)
AddToCache("dsC ontactTypes", DsContactTypes1 )
End If
End Sub
That is correctly converted by the conversion utility to :
private void Page_Load(objec t sender, System.EventArg s e)
{
if (!(Page.IsPostB ack)) {
this.adaptCalls .Fill(this.DsCa lls1);
this.adaptConta cts.Fill(this.D sContacts1);
this.adaptConta ctTypes.Fill(th is.DsContactTyp es1);
AddToCache("ada ptCalls", adaptCalls);
AddToCache("ada ptContacts", adaptContacts);
AddToCache("ada ptContactTypes" , adaptContactTyp es);
AddToCache("dsC alls", DsCalls1);
AddToCache("dsC ontacts", DsContacts1);
AddToCache("dsC ontactTypes", DsContactTypes1 );
}
}
btw, the conversion utility may not do a complete conversion,
or even a completely accurate one, but it sure saves a lot of
typing, since -mostly- checking code for errors is much easier
than writing it.
I'm sure some will disagree on this... ;-)
Juan T. Llibre, ASP.NET MVP
ASP.NET FAQ : http://asp.net.do/faq/
Foros de ASP.NET en Español : http://asp.net.do/foros/
=============== =============== ========
"Bishoy George" <bi****@bishoy. com> wrote in message
news:OM******** ******@TK2MSFTN GP12.phx.gbl... Many thanks Juan for this utility for conversion.
Mr.Newbie:
your code has errors so I can't understand it or even convert it. Still, thank you.
"Juan T. Llibre" <no***********@ nowhere.com> wrote in message
news:ek******** ******@TK2MSFTN GP14.phx.gbl... Why don't you use an online conversion utility ?
http://www.developerfusion.co.uk/uti...btocsharp.aspx
will convert VB.NET to C# ( and C# to VB.NET ) for you.
Juan T. Llibre, ASP.NET MVP
ASP.NET FAQ : http://asp.net.do/faq/
Foros de ASP.NET en Español : http://asp.net.do/foros/
=============== =============== ========
"Bishoy George" <bi****@bishoy. com> wrote in message
news:eR******** ******@TK2MSFTN GP09.phx.gbl...I am very disturbing, but if you please could you write it again in C# because I don't
understand vb.net.
Many Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:eH******** ******@TK2MSFTN GP14.phx.gbl...
Here's a little example which uses a helper function. And yes your right about the
constructor but that was not meant to be tested code just really to point you in the
right direction. In this example, the form is simply a main switchboard which does
not use any data, on the other forms in the application they define the dataset, and
adapter as class level variables and load them from cache in the Page_Load event as
described which can be done with a simple assignment
variableName=ca che("storedIden tifier").
Hope this helps you.
Regards - Mr N. . . .
----------------------
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArg s)
Handles MyBase.Load
'Put user code to initialize the page here
If Not Page.IsPostBack Then
Me.adaptCalls.F ill(Me.DsCalls1 )
Me.adaptContact s.Fill(Me.DsCon tacts1)
Me.adaptContact Types.Fill(Me.D sContactTypes1)
AddToCache("ada ptCalls", adaptCalls)
AddToCache("ada ptContacts", adaptContacts)
AddToCache("ada ptContactTypes" , adaptContactTyp es)
AddToCache("dsC alls", DsCalls1)
AddToCache("dsC ontacts", DsContacts1)
AddToCache("dsC ontactTypes", DsContactTypes1 )
End If
End Sub
Private Sub AddToCache(ByVa l name As String, ByVal item As Object)
If Not IsNothing(Cache (name)) Then
Return
Else
Cache.Add(name, item, Nothing, DateTime.MaxVal ue,
System.TimeSpan .FromDays(20), Caching.CacheIt emPriority.Defa ult, Nothing)
End If
End Sub
"Bishoy George" <bi****@bishoy. com> wrote in message
news:ul******** ******@TK2MSFTN GP11.phx.gbl...
> You are right. But, please write me more specific coding about caching:
> 1- code of caching exactly: as I looked at msdn there is difficult things to set and
> there is no overloading of Cache.Add() that takes 1 parameter as you wrote.
> 2- where exactly to put that caching code?
> Thanks.
>
> "Mr Newbie" <he**@now.com > wrote in message
> news:uV******** ******@tk2msftn gp13.phx.gbl...
>> The problem is that when you click the Dropdown Box, you trigger a postback.
>> Unfortunately, your Page_Load event only fills the dataset during the initial GET.
>> So there is no data to be had when you do your Autopostback.
>>
>> Once a Webform is constructed and the page rendered, the object is destroyed. You
>> need to arrange for the data to be filled on the initial get and saved to the cache
>> for example.
>>
>> cache("ds1)= Ds1
>>
>>
>> and as an else condition to your if not IsPostback
>>
>> ds1 = cache("ds1")
>>
>> page.DataBind() .. . . . .etc
>>
>> PS: This is a common mistake to make.
>>
>> HTH
>>
>>
>>
>> "Bishoy George" <bi****@bishoy. com> wrote in message
>> news:uN******** ********@TK2MSF TNGP14.phx.gbl. ..
>>>I have a dataset called ds1 filled with 2 tables Employees and Customers from
>>>Northwin d database.
>>> I have dropdownList called ddLastName with the following properties:
>>>
>>> ddLastName.Data Source = ds1;
>>> ddLastName.Data Member = "Employees" ;
>>> ddLastName.Data TextField = "LastName";
>>> ddLastName.Data Bind();
>>> ddLastName.Item s.Insert(0,"Sel ect:");
>>>
>>> I have a label called lblDisplay
>>>
>>> I want the label to display the Notes column data of the selected item in the
>>> dropdownList.
>>>
>>> My code is causing a NullReferenceEx ception.
>>> Can anyone find out what is the problem please?
>>>
>>> ------------------------------------
>>> Code: ----------------------------------------------------
>>> <%@ Page language="c#" Codebehind="Web Form9.aspx.cs" AutoEventWireup ="false"
>>> Inherits="WebAp plication2.WebF orm9" %>
>>> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
>>> <HTML>
>>> <HEAD>
>>> <title>WebForm9 </title>
>>> <meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
>>> <meta content="C#" name="CODE_LANG UAGE">
>>> <meta content="JavaSc ript" name="vs_defaul tClientScript">
>>> <meta content="http://schemas.microso ft.com/intellisense/ie5"
>>> name="vs_target Schema">
>>> </HEAD>
>>> <body MS_POSITIONING= "GridLayout ">
>>> <form id="Form1" method="post" runat="server">
>>> <asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px; POSITION: absolute;
>>> TOP: 19px"
>>> runat="server" Width="536px" Height="8px"></asp:Label>
>>> <asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px; POSITION:
>>> absolute; TOP: 152px"
>>> runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
>>> BorderStyle="No ne" BorderWidth="1p x"
>>> BackColor="Whit e" CellPadding="4" >
>>> <FooterStyle ForeColor="#003 399" BackColor="#99C CCC"></FooterStyle>
>>> <SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
>>> BackColor="#009 999"></SelectedItemSty le>
>>> <ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
>>> <HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
>>> BackColor="#003 399"></HeaderStyle>
>>> <PagerStyle HorizontalAlign ="Left" ForeColor="#003 399" BackColor="#99C CCC"
>>> Mode="NumericPa ges"></PagerStyle>
>>> </asp:DataGrid>
>>> <asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px; POSITION:
>>> absolute; TOP: 16px"
>>> runat="server" Width="112px" Height="24px"
>>> AutoPostBack="T rue"></asp:DropDownLis t>
>>> <asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px; POSITION: absolute;
>>> TOP: 48px" runat="server"
>>> Width="272px" Height="16px" ForeColor="Red" >I want to display notes of selected
>>> employee</asp:Label>
>>> <asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px; POSITION: absolute;
>>> TOP: 72px"
>>> runat="server" Width="704px" Height="56px"></asp:Label></form>
>>> </body>
>>> </HTML>
>>>
>>> --------------------------------------------------code
>>> behind--------------------------------------------------------------------------
>>> using System;
>>> using System.Collecti ons;
>>> using System.Componen tModel;
>>> using System.Data;
>>> using System.Data.Sql Client;
>>> using System.Drawing;
>>> using System.Web;
>>> using System.Web.Sess ionState;
>>> using System.Web.UI;
>>> using System.Web.UI.W ebControls;
>>> using System.Web.UI.H tmlControls;
>>>
>>> namespace WebApplication2
>>> {
>>> /// <summary>
>>> /// Summary description for WebForm9.
>>> /// </summary>
>>> public class WebForm9 : System.Web.UI.P age
>>> {
>>> protected DataSet ds1 = new DataSet();
>>> protected System.Web.UI.W ebControls.Labe l lblDisplay;
>>> protected System.Web.UI.W ebControls.Data Grid DataGrid1;
>>> protected System.Web.UI.W ebControls.Labe l lblText;
>>> protected System.Web.UI.W ebControls.Labe l lblSpecific;
>>> protected System.Web.UI.W ebControls.Drop DownList ddLastName;
>>>
>>> private void Page_Load(objec t sender, System.EventArg s e)
>>> {
>>> if(!Page.IsPost Back)
>>> {
>>> string connectionStrin g = "data source =localhost; initial catalog =Northwind;
>>> integrated security=true;" ;
>>> SqlConnection sqlConnection1 = new SqlConnection(c onnectionString );
>>>
>>> SqlCommand sqlCommand1 = new SqlCommand();
>>> SqlDataAdapter sda1 = new SqlDataAdapter( );
>>>
>>> // "dataset defined at class level"
>>> // DataSet ds1 = new DataSet();
>>>
>>> sda1.SelectComm and = sqlCommand1;
>>> sda1.SelectComm and.Connection = sqlConnection1;
>>> sda1.SelectComm and.CommandType = CommandType.Tex t;
>>> sda1.SelectComm and.CommandText = "select * from Employees";
>>>
>>> sda1.Fill(ds1," Employees");
>>>
>>> SqlDataAdapter sda2 = new SqlDataAdapter( );
>>>
>>> sda2.SelectComm and = sqlCommand1;
>>> sda2.SelectComm and.Connection = sqlConnection1;
>>> sda2.SelectComm and.CommandType = CommandType.Tex t;
>>> sda2.SelectComm and.CommandText = "select * from Customers";
>>>
>>> sda2.Fill(ds1," Customers");
>>>
>>> ddLastName.Data Source = ds1;
>>> ddLastName.Data Member = "Employees" ;
>>> ddLastName.Data TextField = "LastName";
>>> ddLastName.Data Bind();
>>> ddLastName.Item s.Insert(0,"Sel ect:");
>>>
>>> // to fill with specific cell data
>>> lblSpecific.Tex t = "Displaying specific Data:<br><br>";
>>> lblSpecific.Tex t += ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
>>>
>>> // to fill the datagrid
>>> DataGrid1.DataS ource = ds1;
>>> DataGrid1.DataM ember = "Employees" ;
>>> DataGrid1.DataB ind();
>>>
>>> }
>>> }
>>>
>>> #region Web Form Designer generated code
>>> override protected void OnInit(EventArg s e)
>>> {
>>> //
>>> // CODEGEN: This call is required by the ASP.NET Web Form Designer.
>>> //
>>> InitializeCompo nent();
>>> base.OnInit(e);
>>> }
>>>
>>> /// <summary>
>>> /// Required method for Designer support - do not modify
>>> /// the contents of this method with the code editor.
>>> /// </summary>
>>> private void InitializeCompo nent()
>>> {
>>> this.ddLastName .SelectedIndexC hanged += new
>>> System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
>>> this.Load += new System.EventHan dler(this.Page_ Load);
>>>
>>> }
>>> #endregion
>>>
>>> private void ddLastName_Sele ctedIndexChange d(object sender, System.EventArg s e)
>>> {
>>> if(ddLastName.S electedIndex != 0)
>>> {
>>> int i = 0;
>>> foreach(DataRow r in ds1.Tables["Employees"].Rows)
>>> {
>>> if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
>>> {
>>> lblDisplay.Text = ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
>>> }
>>> i++;
>>> }
>>> }
>>> else
>>> {
>>> lblDisplay.Text = "";
>>> }
>>> }
>>> }
>>> }
>>>
>>
>>
>
>
My code does NOT have errors. This is from a working project.
"Bishoy George" <bi****@bishoy. com> wrote in message
news:OM******** ******@TK2MSFTN GP12.phx.gbl... Many thanks Juan for this utility for conversion.
Mr.Newbie:
your code has errors so I can't understand it or even convert it. Still,
thank you.
"Juan T. Llibre" <no***********@ nowhere.com> wrote in message
news:ek******** ******@TK2MSFTN GP14.phx.gbl... Why don't you use an online conversion utility ?
http://www.developerfusion.co.uk/uti...btocsharp.aspx
will convert VB.NET to C# ( and C# to VB.NET ) for you.
Juan T. Llibre, ASP.NET MVP
ASP.NET FAQ : http://asp.net.do/faq/
Foros de ASP.NET en Español : http://asp.net.do/foros/
=============== =============== ========
"Bishoy George" <bi****@bishoy. com> wrote in message
news:eR******** ******@TK2MSFTN GP09.phx.gbl...I am very disturbing, but if you please could you write it again in C#
because I don't understand vb.net.
Many Thanks.
"Mr Newbie" <he**@now.com > wrote in message
news:eH******** ******@TK2MSFTN GP14.phx.gbl...
Here's a little example which uses a helper function. And yes your
right about the constructor but that was not meant to be tested code
just really to point you in the right direction. In this example, the
form is simply a main switchboard which does not use any data, on the
other forms in the application they define the dataset, and adapter as
class level variables and load them from cache in the Page_Load event
as described which can be done with a simple assignment
variableName=ca che("storedIden tifier").
Hope this helps you.
Regards - Mr N. . . .
----------------------
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load
'Put user code to initialize the page here
If Not Page.IsPostBack Then
Me.adaptCalls.F ill(Me.DsCalls1 )
Me.adaptContact s.Fill(Me.DsCon tacts1)
Me.adaptContact Types.Fill(Me.D sContactTypes1)
AddToCache("ada ptCalls", adaptCalls)
AddToCache("ada ptContacts", adaptContacts)
AddToCache("ada ptContactTypes" , adaptContactTyp es)
AddToCache("dsC alls", DsCalls1)
AddToCache("dsC ontacts", DsContacts1)
AddToCache("dsC ontactTypes", DsContactTypes1 )
End If
End Sub
Private Sub AddToCache(ByVa l name As String, ByVal item As Object)
If Not IsNothing(Cache (name)) Then
Return
Else
Cache.Add(name, item, Nothing, DateTime.MaxVal ue,
System.TimeSpan .FromDays(20), Caching.CacheIt emPriority.Defa ult,
Nothing)
End If
End Sub
"Bishoy George" <bi****@bishoy. com> wrote in message
news:ul******** ******@TK2MSFTN GP11.phx.gbl...
> You are right. But, please write me more specific coding about
> caching:
> 1- code of caching exactly: as I looked at msdn there is difficult
> things to set and there is no overloading of Cache.Add() that takes 1
> parameter as you wrote.
> 2- where exactly to put that caching code?
> Thanks.
>
> "Mr Newbie" <he**@now.com > wrote in message
> news:uV******** ******@tk2msftn gp13.phx.gbl...
>> The problem is that when you click the Dropdown Box, you trigger a
>> postback. Unfortunately, your Page_Load event only fills the dataset
>> during the initial GET. So there is no data to be had when you do
>> your Autopostback.
>>
>> Once a Webform is constructed and the page rendered, the object is
>> destroyed. You need to arrange for the data to be filled on the
>> initial get and saved to the cache for example.
>>
>> cache("ds1)= Ds1
>>
>>
>> and as an else condition to your if not IsPostback
>>
>> ds1 = cache("ds1")
>>
>> page.DataBind() .. . . . .etc
>>
>> PS: This is a common mistake to make.
>>
>> HTH
>>
>>
>>
>> "Bishoy George" <bi****@bishoy. com> wrote in message
>> news:uN******** ********@TK2MSF TNGP14.phx.gbl. ..
>>>I have a dataset called ds1 filled with 2 tables Employees and
>>>Customer s from Northwind database.
>>> I have dropdownList called ddLastName with the following properties:
>>>
>>> ddLastName.Data Source = ds1;
>>> ddLastName.Data Member = "Employees" ;
>>> ddLastName.Data TextField = "LastName";
>>> ddLastName.Data Bind();
>>> ddLastName.Item s.Insert(0,"Sel ect:");
>>>
>>> I have a label called lblDisplay
>>>
>>> I want the label to display the Notes column data of the selected
>>> item in the dropdownList.
>>>
>>> My code is causing a NullReferenceEx ception.
>>> Can anyone find out what is the problem please?
>>>
>>> ------------------------------------
>>> Code: ----------------------------------------------------
>>> <%@ Page language="c#" Codebehind="Web Form9.aspx.cs"
>>> AutoEventWireup ="false" Inherits="WebAp plication2.WebF orm9" %>
>>> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
>>> <HTML>
>>> <HEAD>
>>> <title>WebForm9 </title>
>>> <meta content="Micros oft Visual Studio .NET 7.1" name="GENERATOR ">
>>> <meta content="C#" name="CODE_LANG UAGE">
>>> <meta content="JavaSc ript" name="vs_defaul tClientScript">
>>> <meta content="http://schemas.microso ft.com/intellisense/ie5"
>>> name="vs_target Schema">
>>> </HEAD>
>>> <body MS_POSITIONING= "GridLayout ">
>>> <form id="Form1" method="post" runat="server">
>>> <asp:Label id="lblDisplay " style="Z-INDEX: 101; LEFT: 144px;
>>> POSITION: absolute; TOP: 19px"
>>> runat="server" Width="536px" Height="8px"></asp:Label>
>>> <asp:DataGrid id="DataGrid1" style="Z-INDEX: 102; LEFT: 24px;
>>> POSITION: absolute; TOP: 152px"
>>> runat="server" Width="672px" Height="120px" BorderColor="#3 366CC"
>>> BorderStyle="No ne" BorderWidth="1p x"
>>> BackColor="Whit e" CellPadding="4" >
>>> <FooterStyle ForeColor="#003 399"
>>> BackColor="#99C CCC"></FooterStyle>
>>> <SelectedItemSt yle Font-Bold="True" ForeColor="#CCF F99"
>>> BackColor="#009 999"></SelectedItemSty le>
>>> <ItemStyle ForeColor="#003 399" BackColor="Whit e"></ItemStyle>
>>> <HeaderStyle Font-Bold="True" ForeColor="#CCC CFF"
>>> BackColor="#003 399"></HeaderStyle>
>>> <PagerStyle HorizontalAlign ="Left" ForeColor="#003 399"
>>> BackColor="#99C CCC" Mode="NumericPa ges"></PagerStyle>
>>> </asp:DataGrid>
>>> <asp:DropDownLi st id="ddLastName " style="Z-INDEX: 103; LEFT: 16px;
>>> POSITION: absolute; TOP: 16px"
>>> runat="server" Width="112px" Height="24px"
>>> AutoPostBack="T rue"></asp:DropDownLis t>
>>> <asp:Label id="lblText" style="Z-INDEX: 104; LEFT: 144px;
>>> POSITION: absolute; TOP: 48px" runat="server"
>>> Width="272px" Height="16px" ForeColor="Red" >I want to display
>>> notes of selected employee</asp:Label>
>>> <asp:Label id="lblSpecific " style="Z-INDEX: 105; LEFT: 16px;
>>> POSITION: absolute; TOP: 72px"
>>> runat="server" Width="704px" Height="56px"></asp:Label></form>
>>> </body>
>>> </HTML>
>>>
>>> --------------------------------------------------code
>>> behind--------------------------------------------------------------------------
>>> using System;
>>> using System.Collecti ons;
>>> using System.Componen tModel;
>>> using System.Data;
>>> using System.Data.Sql Client;
>>> using System.Drawing;
>>> using System.Web;
>>> using System.Web.Sess ionState;
>>> using System.Web.UI;
>>> using System.Web.UI.W ebControls;
>>> using System.Web.UI.H tmlControls;
>>>
>>> namespace WebApplication2
>>> {
>>> /// <summary>
>>> /// Summary description for WebForm9.
>>> /// </summary>
>>> public class WebForm9 : System.Web.UI.P age
>>> {
>>> protected DataSet ds1 = new DataSet();
>>> protected System.Web.UI.W ebControls.Labe l lblDisplay;
>>> protected System.Web.UI.W ebControls.Data Grid DataGrid1;
>>> protected System.Web.UI.W ebControls.Labe l lblText;
>>> protected System.Web.UI.W ebControls.Labe l lblSpecific;
>>> protected System.Web.UI.W ebControls.Drop DownList ddLastName;
>>>
>>> private void Page_Load(objec t sender, System.EventArg s e)
>>> {
>>> if(!Page.IsPost Back)
>>> {
>>> string connectionStrin g = "data source =localhost; initial
>>> catalog =Northwind; integrated security=true;" ;
>>> SqlConnection sqlConnection1 = new
>>> SqlConnection(c onnectionString );
>>>
>>> SqlCommand sqlCommand1 = new SqlCommand();
>>> SqlDataAdapter sda1 = new SqlDataAdapter( );
>>>
>>> // "dataset defined at class level"
>>> // DataSet ds1 = new DataSet();
>>>
>>> sda1.SelectComm and = sqlCommand1;
>>> sda1.SelectComm and.Connection = sqlConnection1;
>>> sda1.SelectComm and.CommandType = CommandType.Tex t;
>>> sda1.SelectComm and.CommandText = "select * from Employees";
>>>
>>> sda1.Fill(ds1," Employees");
>>>
>>> SqlDataAdapter sda2 = new SqlDataAdapter( );
>>>
>>> sda2.SelectComm and = sqlCommand1;
>>> sda2.SelectComm and.Connection = sqlConnection1;
>>> sda2.SelectComm and.CommandType = CommandType.Tex t;
>>> sda2.SelectComm and.CommandText = "select * from Customers";
>>>
>>> sda2.Fill(ds1," Customers");
>>>
>>> ddLastName.Data Source = ds1;
>>> ddLastName.Data Member = "Employees" ;
>>> ddLastName.Data TextField = "LastName";
>>> ddLastName.Data Bind();
>>> ddLastName.Item s.Insert(0,"Sel ect:");
>>>
>>> // to fill with specific cell data
>>> lblSpecific.Tex t = "Displaying specific Data:<br><br>";
>>> lblSpecific.Tex t +=
>>> ds1.Tables["Employees"].Rows[0]["Notes"].ToString();
>>>
>>> // to fill the datagrid
>>> DataGrid1.DataS ource = ds1;
>>> DataGrid1.DataM ember = "Employees" ;
>>> DataGrid1.DataB ind();
>>>
>>> }
>>> }
>>>
>>> #region Web Form Designer generated code
>>> override protected void OnInit(EventArg s e)
>>> {
>>> //
>>> // CODEGEN: This call is required by the ASP.NET Web Form
>>> Designer.
>>> //
>>> InitializeCompo nent();
>>> base.OnInit(e);
>>> }
>>>
>>> /// <summary>
>>> /// Required method for Designer support - do not modify
>>> /// the contents of this method with the code editor.
>>> /// </summary>
>>> private void InitializeCompo nent()
>>> {
>>> this.ddLastName .SelectedIndexC hanged += new
>>> System.EventHan dler(this.ddLas tName_SelectedI ndexChanged);
>>> this.Load += new System.EventHan dler(this.Page_ Load);
>>>
>>> }
>>> #endregion
>>>
>>> private void ddLastName_Sele ctedIndexChange d(object sender,
>>> System.EventArg s e)
>>> {
>>> if(ddLastName.S electedIndex != 0)
>>> {
>>> int i = 0;
>>> foreach(DataRow r in ds1.Tables["Employees"].Rows)
>>> {
>>> if(r["LastName"].ToString() == ddLastName.Sele ctedItem.Text)
>>> {
>>> lblDisplay.Text =
>>> ds1.Tables["Employees"].Rows[i]["Notes"].ToString();
>>> }
>>> i++;
>>> }
>>> }
>>> else
>>> {
>>> lblDisplay.Text = "";
>>> }
>>> }
>>> }
>>> }
>>>
>>
>>
>
>
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