ListControl.OnSelectedIndexChanged Method
Raises the SelectedIndexChanged event. This allows you to provide a custom handler for the event.
Assembly: System.Web (in System.Web.dll)
Parameters
- e
- Type: System.EventArgs
A System.EventArgs that contains the event data.
The SelectedIndexChanged event is raised when the selection from the list control changes between posts to the server.
 Note: |
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A list control must persist some values between posts to the server for this event to work correctly. Be sure that view state is enabled for the list control. |
Raising an event invokes the event handler through a delegate. For more information, see Consuming Events.
The OnSelectedIndexChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.
Notes to Inheritors:When overriding OnSelectedIndexChanged in a derived class, be sure to call the base class's OnSelectedIndexChanged method so that registered delegates receive the event.
The following example demonstrates how to specify and code a handler for the SelectedIndexChanged event to display the selection made by the user.
<%@ Page Language="C#" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <!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" > <script language="c#" runat="server"> ICollection CreateDataSource() { DataTable dt = new DataTable(); DataRow dr; dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32))); dt.Columns.Add(new DataColumn("StringValue", typeof(string))); dt.Columns.Add(new DataColumn("DateTimeValue", typeof(DateTime))); dt.Columns.Add(new DataColumn("BoolValue", typeof(bool))); dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double))); for (int i = 0; i < 9; i++) { dr = dt.NewRow(); dr[0] = i; dr[1] = "Item " + i.ToString(); dr[2] = DateTime.Now; dr[3] = (i % 2 != 0) ? true : false; dr[4] = 1.23 * (i+1); dt.Rows.Add(dr); } DataView dv = new DataView(dt); return dv; } void Page_Load(Object sender, EventArgs e) { if (!IsPostBack) { RadioButtonList1.DataSource = CreateDataSource(); RadioButtonList1.DataTextField="StringValue"; RadioButtonList1.DataValueField="CurrencyValue"; RadioButtonList1.DataBind(); } } void Index_Changed(Object sender, EventArgs e) { Label1.Text = "You selected " + RadioButtonList1.SelectedItem.Text + " with a value of $" + RadioButtonList1.SelectedItem.Value + "."; } </script> <head runat="server"> <title>ASP.NET Example</title> </head> <body> <form id="form1" runat="server"> <asp:RadioButtonList id="RadioButtonList1" OnSelectedIndexChanged="Index_Changed" AutoPostBack="true" runat="server"/> <br /> <asp:Label id="Label1" runat="server"/> </form> </body> </html>
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
