HtmlInputRadioButton.OnPreRender(EventArgs) Methode

Referenz

Definition

Namespace:: System.Web.UI.HtmlControls

Assembly:: System.Web.dll

Wichtig

Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.

Löst das PreRender-Ereignis aus und registriert das HtmlInputRadioButton-Steuerelement als ein Steuerelement, für das eine Postbackbehandlung erforderlich ist.

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)

Parameter

e: EventArgs

Ein EventArgs, das die Ereignisdaten enthält.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die OnPreRender -Methode überschrieben wird, sodass ein Title Attribut in einem benutzerdefinierten HtmlInputRadioButton Serversteuerelement hinzugefügt wird.

<%@ 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

Hinweise

Die OnPreRender -Methode wird kurz vor dem Rendern des Steuerelements HtmlInputRadioButton aufgerufen.

Die OnPreRender -Methode wird in erster Linie von Steuerelemententwicklern verwendet, die die Funktionalität des Steuerelements HtmlInputRadioButton erweitern.

Gilt für:

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