Grid Disappears (WebForm)

[Steve]

Hi

I have a db with 2 tables that I want to bind to a grid depending on a
selection in a Dropdownlist
Also I want to be able to select a row from the gris to fill some
textboxes.
The databases are static in that they will not be updated they are just
for viewing

I have everything working but not to perfection

A few issues I am trying to solve
1) If I select a row from the select button - can I avoid a postback and

just fill the textboxes with the
data in the grid row

2)It seems that I have to have the Grid.Bind() in the Page_Load - I
thought I would only need to load the
Datasets once and just re-bind to Grid????

3)The one problem I do have is that if I hit a CommandButton that
actually needs to go to the server
I lose the grid
Thanks
Steve
Dim MyConnection As SqlConnection
Dim DS As DataSet
Dim DS2 As DataSet

Public Class DLLClass
<DllImport("Pay ment.dll")> _
Public Shared Function _
CalcPaymentCH(B yVal lLOS As Integer, ByVal dCW As Double, ByVal
lLTP As Integer, ByVal lHTP As Integer, ByVal dALOS As Double, ByVal
dCHF As Double, ByVal dFACTOR As Double) As Double
End Function

End Class
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load

MyConnection = New SqlConnection(" Data Source=localhos t;Initial
Catalog=Stats;U ser Id=sa;Password= ;")

If Not (IsPostBack) Then ' Evals true first time browser hits
the page
'Put user code to initialize the page here
'BindGrid() 'Should be here ????

ddlFormula.Item s.Add("")
ddlFormula.Item s.Add("Swiss 2003")
ddlFormula.Item s.Add("Swiss 2004")

txtCHF.Text = "5000"
txtFactor.Text = "0.7"
txtHTPF.Text = "2.43"
txtLTPF.Text = "2.0"

txtLTPF.Visible = False
txtHTPF.Visible = False
lblLTPF.Visible = False
lblHTPF.Visible = False

End If

BindGrid()

End Sub

Private Sub ddlFormula_Sele ctedIndexChange d(ByVal sender As
System.Object, ByVal e As System.EventArg s) Handles
ddlFormula.Sele ctedIndexChange d

If (ddlFormula.Sel ectedValue = "Swiss 2004") Then
txtLTPF.Visible = True
txtHTPF.Visible = True
lblLTPF.Visible = True
lblHTPF.Visible = True
Datagrid1.DataS ource = DS2.Tables("CHA P2004").Default View
Datagrid1.DataB ind()
Else
txtLTPF.Visible = False
txtHTPF.Visible = False
lblLTPF.Visible = False
lblHTPF.Visible = False
Datagrid1.DataS ource = DS.Tables("CHAP 2003").DefaultV iew
Datagrid1.DataB ind()
End If

End Sub

Private Sub BindGrid()

Dim MyCommand As SqlDataAdapter

MyCommand = New SqlDataAdapter( "SELECT * FROM CHAP2003",
MyConnection)
DS = New DataSet
MyCommand.Fill( DS, "CHAP2003")

MyCommand = New SqlDataAdapter( "SELECT * FROM CHAP2004",
MyConnection)
DS2 = New DataSet
MyCommand.Fill( DS2, "CHAP2004")

'Datagrid1.Data Source = DS.Tables("CHAP 2003").DefaultV iew
'Datagrid1.Data Bind()

End Sub
Private Sub btnCalculate_Cl ick(ByVal sender As System.Object, ByVal
e As System.EventArg s) Handles btnCalculate.Cl ick
Dim dPayment As Double
If (ddlFormula.Sel ectedValue = "Swiss 2003") Then
dPayment = DLLClass.CalcPa ymentCH(20, 1.5, 5, 15, 10.5,
5000.0, 0.7)
ElseIf (ddlFormula.Sel ectedValue = "Swiss 2004") Then

End If
txtPayment.Text = Str(dPayment)
End Sub

Private Sub Datagrid1_Selec tedIndexChanged (ByVal sender As Object,
ByVal e As System.EventArg s) Handles Datagrid1.Selec tedIndexChanged
txtDRG.Text = Datagrid1.Selec tedItem.Cells(1 ).Text.ToString ()
txtWT.Text = Datagrid1.Selec tedItem.Cells(2 ).Text.ToString ()
txtALOS.Text = Datagrid1.Selec tedItem.Cells(3 ).Text.ToString ()
txtHTP1.Text = Datagrid1.Selec tedItem.Cells(4 ).Text.ToString ()
txtLTP.Text = Datagrid1.Selec tedItem.Cells(5 ).Text.ToString ()
End Sub
End Class
<div style="Z-INDEX: 122; LEFT: 205px; OVERFLOW: auto; WIDTH: 250px;
POSITION: absolute; TOP: 62px; HEIGHT: 185px"><asp:dat agrid
id="Datagrid1" runat="server" EnableViewState ="False" Width="200px">
<AlternatingIte mStyle BorderColor="Wh ite"
BackColor="#C0C 0FF"></AlternatingItem Style>
<Columns>
<asp:ButtonColu mn Text="Select"
CommandName="Se lect"></asp:ButtonColum n>
</Columns>
</asp:datagrid></div>

<asp:button id="btnCalculat e" style="Z-INDEX: 110; LEFT: 69px; POSITION:

absolute; TOP: 534px"
runat="server" Height="23px" Width="166px" Text="Calculate
Payment"></asp:button>

[alex bowers]

Hi Steve,
For more information on your questions I'd recommend
reading an article on displaying data in datagrids, there
are a lot of in-depth ones on the web that are easily
accessible.
Briefly:
1) If you want to avoid a postback you'll need to
populate the textboxes using client-side javascript that
fires on the onclick() event of your button. this isn't
easily supported by asp.net server controls, but can be
accomplished.

2) Don't databind() the grid in the Page Load event - in
fact, do the binding inside a {[C#]if (!ispostback)}
condition - this way the viewstate of the datagrid
will 'remember' what was in the grid and re-display it.
If the contents of the grid change you will need to
rebind, remember to obtain the data again first though.

3) Again, you're probably rebinding to the datagrid when
the command-button is hit but there isn't any data to
bind to. Make sure that (a) if you want to rebind, get
the data first; or (b) don't rebind - and the datagrid
will load from its viewstate.

hth
alex

-----Original Message-----
Hi

I have a db with 2 tables that I want to bind to a grid depending on aselection in a Dropdownlist
Also I want to be able to select a row from the gris to fill sometextboxes.
The databases are static in that they will not be updated they are justfor viewing

I have everything working but not to perfection

A few issues I am trying to solve
1) If I select a row from the select button - can I avoid a postback and
just fill the textboxes with the
data in the grid row

2)It seems that I have to have the Grid.Bind() in the Page_Load - Ithought I would only need to load the
Datasets once and just re-bind to Grid????

3)The one problem I do have is that if I hit a CommandButton thatactually needs to go to the server
I lose the grid
Thanks
Steve
Dim MyConnection As SqlConnection
Dim DS As DataSet
Dim DS2 As DataSet

Public Class DLLClass
<DllImport("Pay ment.dll")> _
Public Shared Function _
CalcPaymentCH(B yVal lLOS As Integer, ByVal dCW As Double, ByVallLTP As Integer, ByVal lHTP As Integer, ByVal dALOS As Double, ByValdCHF As Double, ByVal dFACTOR As Double) As Double
End Function

End Class
Private Sub Page_Load(ByVal sender As System.Object, ByVal e AsSystem.EventAr gs) Handles MyBase.Load

MyConnection = New SqlConnection(" Data Source=localhos t;InitialCatalog=Stats; User Id=sa;Password= ;")

If Not (IsPostBack) Then ' Evals true first time browser hitsthe page
'Put user code to initialize the page here
'BindGrid() 'Should be here ????

ddlFormula.Item s.Add("")
ddlFormula.Item s.Add("Swiss 2003")
ddlFormula.Item s.Add("Swiss 2004")

txtCHF.Text = "5000"
txtFactor.Text = "0.7"
txtHTPF.Text = "2.43"
txtLTPF.Text = "2.0"

txtLTPF.Visible = False
txtHTPF.Visible = False
lblLTPF.Visible = False
lblHTPF.Visible = False

End If

BindGrid()

End Sub

Private Sub ddlFormula_Sele ctedIndexChange d(ByVal sender AsSystem.Objec t, ByVal e As System.EventArg s) Handles
ddlFormula.Sel ectedIndexChang ed

If (ddlFormula.Sel ectedValue = "Swiss 2004") Then
txtLTPF.Visible = True
txtHTPF.Visible = True
lblLTPF.Visible = True
lblHTPF.Visible = True
Datagrid1.DataS ource = DS2.Tables ("CHAP2004").De faultView Datagrid1.DataB ind()
Else
txtLTPF.Visible = False
txtHTPF.Visible = False
lblLTPF.Visible = False
lblHTPF.Visible = False
Datagrid1.DataS ource = DS.Tables ("CHAP2003").De faultView Datagrid1.DataB ind()
End If

End Sub

Private Sub BindGrid()

Dim MyCommand As SqlDataAdapter

MyCommand = New SqlDataAdapter( "SELECT * FROM CHAP2003",MyConnection )
DS = New DataSet
MyCommand.Fill( DS, "CHAP2003")

MyCommand = New SqlDataAdapter( "SELECT * FROM CHAP2004",MyConnection )
DS2 = New DataSet
MyCommand.Fill( DS2, "CHAP2004")

'Datagrid1.Data Source = DS.Tables ("CHAP2003").De faultView 'Datagrid1.Data Bind()

End Sub
Private Sub btnCalculate_Cl ick(ByVal sender As System.Object, ByVale As System.EventArg s) Handles btnCalculate.Cl ick
Dim dPayment As Double
If (ddlFormula.Sel ectedValue = "Swiss 2003") Then
dPayment = DLLClass.CalcPa ymentCH(20, 1.5, 5, 15, 10.5,5000.0, 0.7)
ElseIf (ddlFormula.Sel ectedValue = "Swiss 2004") Then
End If
txtPayment.Text = Str(dPayment)
End Sub

Private Sub Datagrid1_Selec tedIndexChanged (ByVal sender As Object,ByVal e As System.EventArg s) Handles Datagrid1.Selec tedIndexChanged txtDRG.Text = Datagrid1.Selec tedItem.Cells (1).Text.ToStri ng() txtWT.Text = Datagrid1.Selec tedItem.Cells (2).Text.ToStri ng() txtALOS.Text = Datagrid1.Selec tedItem.Cells (3).Text.ToStri ng() txtHTP1.Text = Datagrid1.Selec tedItem.Cells (4).Text.ToStri ng() txtLTP.Text = Datagrid1.Selec tedItem.Cells (5).Text.ToStri ng() End Sub
End Class
<div style="Z-INDEX: 122; LEFT: 205px; OVERFLOW: auto; WIDTH: 250px;POSITION: absolute; TOP: 62px; HEIGHT: 185px"><asp:dat agridid="Datagrid 1" runat="server" EnableViewState ="False" Width="200px"> <AlternatingIte mStyle BorderColor="Wh ite"
BackColor="#C0 C0FF"></AlternatingItem Style>
<Columns>
<asp:ButtonColu mn Text="Select"
CommandName="S elect"></asp:ButtonColum n>
</Columns>
</asp:datagrid></div>

<asp:button id="btnCalculat e" style="Z-INDEX: 110; LEFT: 69px; POSITION:
absolute; TOP: 534px"
runat="server" Height="23px" Width="166px" Text="CalculatePayment"></asp:button>

.