Path for Missing Class in VWD2010 Express

Yiyi

New Member

Join Date: Oct 2012
Posts: 2

Path for Missing Class in VWD2010 Express

Oct 17 '12, 10:11 AM

Hi all.

I have an issue using Ajax Control Toolkit ComboBox.
Here is my test markup page:

Code:

<%@ Page Language="C#" 
    AutoEventWireup="true" 
    CodeFile="Default2.aspx.cs" 
    Inherits="Default2" %> 
<%@ Register Assembly="AjaxControlToolkit"
    Namespace="AjaxControlToolkit"
    TagPrefix="asp" %> 

<!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></title> 
</head> 
<body> 
<form id="form1" runat="server"> 
  <asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"></asp:ToolkitScriptManager> 
  <div> 
    <asp:CheckBox ID="CheckBox1" runat="server" AutoPostBack="True" /> 
    <% if (CheckBox1.Checked)
{ %>
    <asp:ComboBox ID="ComboBox1" runat="server">
    </asp:ComboBox> 
<% } %> 
  </div> 
</form> 
</body> 
</html>

After CheckBox1 rises PostBack I get a NullReferenceEx ception in the method

AjaxControlTool  Kit.ComboBox.Sy  stem.Web.UI.IPo  stBackDataHandl  er.LoadPostData  (stringpostData  Key, System.Collecti  ons.Specialized  .Name.ValueColl  ection postCollection)

and Visual Web Developer 2010 Express asks me the path of the Class ComboBox.cs that I don't have.

Without <% if { } %> the ComboBox works fine.

Can anyone help me?

Thank you.

Last edited by Frinavale; Oct 25 '12, 01:30 PM. Reason: Formatted code so that it is easier to read.

Tags: None

Frinavale

Recognized Expert Expert

Join Date: Oct 2006

Posts: 9749
#2

Oct 25 '12, 01:33 PM

Instead of using the <%if{}%>, consider setting the ComboBox'sVisible property to the Checked property of the CheckBox in the method that handles the CheckBox1's CheckedChanged event.

-Frinny
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Path for Missing Class in VWD2010 Express

Path for Missing Class in VWD2010 Express

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