asp: CheckBox changed event (C#) : CheckBox « ASP.net Controls « ASP.NET Tutorial






File: Default.aspx

<%@ Page language="c#" Inherits="EventTracker" CodeFile="Default.aspx.cs" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
 "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
  <title>Event Tracker</title>
</head>
<body>
  <form id="Form1" runat="server">
    <div>       
      <h1>Controls being monitored for change events:</h1>
      <asp:TextBox ID="txt" 
                   runat="server" 
                   AutoPostBack="true"
                   OnTextChanged="CtrlChanged" />
      <br /><br />
      <asp:CheckBox ID="chk" 
                    runat="server" 
                    AutoPostBack="true"
                    OnCheckedChanged="CtrlChanged"/>
      <br /><br />
      <asp:RadioButton ID="opt1" runat="server" GroupName="Sample"
       AutoPostBack="true" OnCheckedChanged="CtrlChanged"/>
      <asp:RadioButton ID="opt2" runat="server" GroupName="Sample"
       AutoPostBack="true" OnCheckedChanged="CtrlChanged"/>
      <br /><br /><br /> 
       <h1>List of events:</h1>
      <asp:ListBox ID="lstEvents" runat="server" Width="355px"
       Height="305px" /><br />      
    </div>
  </form>
</body>
</html>


File: Default.aspx.cs

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;


public partial class EventTracker : System.Web.UI.Page
{

  protected void Page_Load(object sender, System.EventArgs e)
  {
     Log("<< Page_Load >>");
  }

  private void Log(string entry)
  {
    lstEvents.Items.Add(entry);
    lstEvents.SelectedIndex = lstEvents.Items.Count - 1;
  }

  protected void Page_PreRender(object sender, System.EventArgs e)
  {
    Log("Page_PreRender");
  }

  protected void CtrlChanged(Object sender, EventArgs e)
  {
    string ctrlName = ((Control)sender).ID;
    Log(ctrlName + " Changed");
  }

}








3.11.CheckBox
3.11.1.Import properties, events and methods of CheckBox control
3.11.2.Get selected CheckBox
3.11.3.asp: CheckBox changed event (C#)
3.11.4.use the AutoPostBack property to post the form to the server automatically when the check box is checked or unchecked.