HtmlButton.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 Clientskript für das Generieren des Postbacks.

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 Ereignisdaten enthält.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die OnPreRender -Methode in einem benutzerdefinierten Serversteuerelement überschrieben wird, sodass immer fett formatierter HtmlButton Text angezeigt wird.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<!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 HtmlButton - OnPreRender - C# Example</title>
    <script runat="server">
      void Page_Load(Object sender, EventArgs e)
      {
        HtmlButton1.Attributes.Add("onclick","alert('Hello client-side world.');");
      }

      void HtmlButton1_ServerClick(Object sender, EventArgs e)
      {
        Div1.InnerHtml = "Hello server-side world.";
      }
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom HtmlButton - OnPreRender - C# Example</h3>

      <aspSample:CustomHtmlButtonOnPreRender
        id="HtmlButton1"
        runat="server"
        type="button"
        onserverclick="HtmlButton1_ServerClick"
        name="HtmlButton1">Html Button</aspSample:CustomHtmlButtonOnPreRender>  

      <div id="Div1" runat="server"
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
    </form>
  </body>
</html>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<!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 HtmlButton - OnPreRender - Visual Basic Example</title>
    <script runat="server">
      Sub Page_Load(sender As Object, e As EventArgs)
        HtmlButton1.Attributes.Add("onclick", "alert('Hello client-side world.');")
      End Sub

      Sub HtmlButton1_ServerClick(sender As Object, e As EventArgs)
        Div1.InnerHtml = "Hello server-side world."
      End Sub
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom HtmlButton - OnPreRender - Visual Basic Example</h3>

      <aspSample:CustomHtmlButtonOnPreRender
        id="HtmlButton1"
        runat="server"
        type="button"
        onserverclick="HtmlButton1_ServerClick"
        name="HtmlButton1">Button</aspSample:CustomHtmlButtonOnPreRender>  

      <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 CustomHtmlButtonOnPreRender : System.Web.UI.HtmlControls.HtmlButton
    {
        protected override void OnPreRender(System.EventArgs e)
        {
            // Call the base class's OnPreRender method.
            base.OnPreRender(e);

            // Always display the HtmlButton with bold text.
            this.Style.Add("font-weight", "bold");
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls

    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomHtmlButtonOnPreRender
        Inherits System.Web.UI.HtmlControls.HtmlButton

        Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)

            ' Call the base class's OnPreRender method.
            MyBase.OnPreRender(e)

            ' Always display the HtmlButton with bold text.
            Me.Style.Add("font-weight", "bold")
        End Sub
    End Class

End Namespace

Hinweise

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

Gilt für:

Freigeben über