Hi All,
I have created my own WebControl and want to add it in my aspx page at
runtime.
it's compiling perfectly, but when i m going to execute, it gives me
error of "Object reference not set to an instance of an object." in my
server control (ascx.cs file)
There is a table in my user control with id "tdCell".
I'm creating a Label control at runtime in Page_Load of user control,
and want to add it in the "tdCell" by just tdCell.Controls.Add()....
There is a Panel on my aspx page with id "TBarPanel", and want to add
the user control at runtime. but i m getting error.
Any idea...I tried panel/placeholder/table every thing but it's not
working.
I also tried using LoadControl("MyControl.ascx"), but it's also not
working.
I put all code and error string for your reference.
Thanks & Regards,
Rushikesh
////////// MyControl.ascx /////////////
<%@ Control Language="C#" AutoEventWireup="true"
CodeFile="MyControl.ascx.cs" Inherits="MyControl" %>
<table cellpadding="0" cellspacing="0">
<tr>
<td id="tdCell" runat="server"></td>
</tr>
</table>
////////// MyControl.ascx.cs /////////////
using System;
using System.Data;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class MyControl: System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
Label lbl = new Label();
lbl.Text = "Hello";
tdCell.Controls.Add(lbl);
}
}
//// //// MyControl_Test.aspx /////////
<%@ Page Language="C#" AutoEventWireup="true"
CodeFile="MyControl_Test.aspx.cs" Inherits="MyControl_Test" %>
<%@ Register Src="MyControl.ascx" TagName="MyControl" TagPrefix="uc1"
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Panel ID="TBarPanel" runat="server" Height="42px"
Width="100%">
</asp:Panel>
</form>
</body>
</html>
//// //// MyControl_Test.aspx.cs /////////
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class TimeBarCtrl_Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
MyControl myctrl1 = new MyControl();
placeUserControls.AddTimeBarSegment(myctrl1);
MyControl myctrl2 = new MyControl();
placeUserControls.AddTimeBarSegment(myctrl2);
MyControl myctrl3 = new MyControl();
placeUserControls.AddTimeBarSegment(myctrl3);
}
}
////////////////////**********************Error
Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not
set to an instance of an object.
Source Error:
Line 54: Label lbl = new Label();
Line 55: lbl.Text = "Hello";
Line 56: tdCell.Controls.Add(lbl);
Line 57:
Line 58:
Source File: d:\inetpub\wwwroot\MACT\Interface\TimeBarCtrl.ascx .cs
Line: 56
Stack Trace:
[NullReferenceException: Object reference not set to an instance of an
object.]
TimeBarCtrl.Page_Load(Object sender, EventArgs e) in
d:\inetpub\wwwroot\MACT\Interface\TimeBarCtrl.ascx .cs:56
System.Web.Util.CalliHelper.EventArgFunctionCaller (IntPtr fp, Object
o, Object t, EventArgs e) +13
System.Web.Util.CalliEventHandlerDelegateProxy.Cal lback(Object
sender, EventArgs e) +45
System.Web.UI.Control.OnLoad(EventArgs e) +80
System.Web.UI.Control.LoadRecursive() +49
System.Web.UI.Control.LoadRecursive() +132
System.Web.UI.Control.LoadRecursive() +132
System.Web.UI.Control.LoadRecursive() +132
System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
+3710
