HtmlInputRadioButton.OnPreRender(EventArgs) Method
Important
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Raises the PreRender event and registers the HtmlInputRadioButton control as one that requires postback handling.
protected:
override void OnPreRender(EventArgs ^ e);
protected public:
override void OnPreRender(EventArgs ^ e);
protected override void OnPreRender (EventArgs e);
protected internal override void OnPreRender (EventArgs e);
override this.OnPreRender : EventArgs -> unit
Protected Overrides Sub OnPreRender (e As EventArgs)
Protected Friend Overrides Sub OnPreRender (e As EventArgs)
The following code example demonstrates how to override the OnPreRender method so that it adds a Title
attribute in a custom HtmlInputRadioButton server control.
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<!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><title>Custom HtmlInputRadioButton - OnPreRender - C# Example</title>
<script runat="server">
void Page_Load(Object sender, EventArgs e)
{
Div1.InnerHtml = "";
}
void HtmlInputRadioButtonGroup1_ServerChange(object sender, System.EventArgs e)
{
// Diplay the value of the selected HtmlInputRadioButton control.
System.Web.UI.HtmlControls.HtmlInputRadioButton htmlInputRadioButtonGroup1 = (System.Web.UI.HtmlControls.HtmlInputRadioButton) sender;
Div1.InnerHtml = "You change your selection to: " + htmlInputRadioButtonGroup1.Value;
}
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlInputRadioButton - OnPreRender - C# Example</h3>
<aspSample:CustomHtmlInputRadioButtonOnPreRender
id="HtmlInputRadioButton1"
name="HtmlInputRadioButtonGroup1"
runat="server"
type="radio" checked
onserverchange="HtmlInputRadioButtonGroup1_ServerChange"
value="HtmlInputRadioButton1">HtmlInputRadioButton1
</aspSample:CustomHtmlInputRadioButtonOnPreRender>
<br />
<aspSample:CustomHtmlInputRadioButtonOnPreRender
id="HtmlInputRadioButton2"
name="HtmlInputRadioButtonGroup1"
runat="server"
type="radio"
onserverchange="HtmlInputRadioButtonGroup1_ServerChange"
value="HtmlInputRadioButton2">HtmlInputRadioButton2
</aspSample:CustomHtmlInputRadioButtonOnPreRender>
<p>
<input type="submit" value="Submit" id="Submit1" name="Submit1" runat="server" />
</p>
<div
id="Div1"
runat="server"
style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<!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><title>Custom HtmlInputRadioButton - OnPreRender - Visual Basic Example</title>
<script runat="server">
Sub Page_Load(sender As Object, e As EventArgs)
Div1.InnerHtml = ""
End Sub
Sub HtmlInputRadioButtonGroup1_ServerChange(sender As Object, e As System.EventArgs)
Dim htmlInputRadioButtonGroup1 As System.Web.UI.HtmlControls.HtmlInputRadioButton = CType(sender, System.Web.UI.HtmlControls.HtmlInputRadioButton)
Div1.InnerHtml = "You change your selection to: " & htmlInputRadioButtonGroup1.Value
End Sub
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlInputRadioButton - OnPreRender - Visual Basic Example</h3>
<aspSample:CustomHtmlInputRadioButtonOnPreRender
id="HtmlInputRadioButton1"
name="HtmlInputRadioButtonGroup1"
runat="server"
type="radio" checked
onserverchange="HtmlInputRadioButtonGroup1_ServerChange"
value="HtmlInputRadioButton1">HtmlInputRadioButton1
</aspSample:CustomHtmlInputRadioButtonOnPreRender>
<br />
<aspSample:CustomHtmlInputRadioButtonOnPreRender
id="HtmlInputRadioButton2"
name="HtmlInputRadioButtonGroup1"
runat="server"
type="radio"
onserverchange="HtmlInputRadioButtonGroup1_ServerChange"
value="HtmlInputRadioButton2">HtmlInputRadioButton2
</aspSample:CustomHtmlInputRadioButtonOnPreRender>
<p>
<input type="submit" value="Submit" id="Submit1" name="Submit1" runat="server" />
</p>
<div
id="Div1"
runat="server"
style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomHtmlInputRadioButtonOnPreRender : System.Web.UI.HtmlControls.HtmlInputRadioButton
{
protected override void OnPreRender(System.EventArgs e)
{
// Run the OnPreRender method on the base class.
base.OnPreRender(e);
// Add a Title attribute.
this.Attributes.Add("title", "Option " + this.Value);
}
}
}
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomHtmlInputRadioButtonOnPreRender
Inherits System.Web.UI.HtmlControls.HtmlInputRadioButton
Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
' Run the OnPreRender method on the base class.
MyBase.OnPreRender(e)
' Add a Title attribute.
Me.Attributes.Add("title", "Option " + Me.Value)
End Sub
End Class
The OnPreRender method is called just prior to rendering the HtmlInputRadioButton control.
The OnPreRender method is used primarily by control developers extending the functionality of the HtmlInputRadioButton control.
Product | Versions |
---|---|
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
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