HtmlInputButton.OnPreRender-Methode

Löst das OnPreRender-Ereignis aus und registriert das Clientskript für das Generieren des Postbacks.

Namespace: System.Web.UI.HtmlControls
Assembly: System.Web (in system.web.dll)

Syntax

'Declaration
Protected Friend Overrides Sub OnPreRender ( _
    e As EventArgs _
)
'Usage
Dim e As EventArgs

Me.OnPreRender(e)

protected internal override void OnPreRender (
    EventArgs e
)

protected public:
virtual void OnPreRender (
    EventArgs^ e
) override

protected void OnPreRender (
    EventArgs e
)

protected internal override function OnPreRender (
    e : EventArgs
)

Parameter

e
Ein EventArgs, das die Ereignisdaten enthält.

Hinweise

Die OnPreRender-Methode überschreibt die Control.OnPreRender-Methode. OnPreRender wird hauptsächlich von Steuerelemententwicklern verwendet.

Beispiel

Im folgenden Codebeispiel wird das Überschreiben der OnPreRender-Methode veranschaulicht, sodass diese immer ein benutzerdefiniertes HtmlInputButton-Steuerelement mit fett formatiertem Text anzeigt.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<HTML>
  <HEAD>
    <title>Custom HtmlInputButton - OnPreRender - Visual Basic Example</title>
    <script runat="server">
      Sub Page_Load(sender As Object, e As EventArgs)
        HtmlInputButton1.Attributes.Add("onclick", "alert('Hello client-side world.');")
      End Sub

      Sub HtmlInputButton1_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 HtmlInputButton - OnPreRender - Visual Basic Example</h3>

      <aspSample:CustomHtmlInputButtonOnPreRender
        id="HtmlInputButton1"
        runat="server"
        type="button"
        onserverclick="HtmlInputButton1_ServerClick"
        value="Html Input Button"
        name="HtmlInputButton1">&nbsp;&nbsp;

      <DIV id="Div1" runat="server"
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px"
        ms_positioning="FlowLayout" />
    </form>
  </body>
</HTML>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<HTML>
  <HEAD>
    <title>Custom HtmlInputButton - OnPreRender - C# Example</title>
    <script runat="server">
      void Page_Load(Object sender, EventArgs e)
      {
        HtmlInputButton1.Attributes.Add("onclick","alert('Hello client-side world.');");
      }

      void HtmlInputButton1_ServerClick(Object sender, EventArgs e)
      {
        Div1.InnerHtml = "Hello server-side world.";
      }
    </script>
  </HEAD>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom HtmlInputButton - OnPreRender - C# Example</h3>

      <aspSample:CustomHtmlInputButtonOnPreRender
        id="HtmlInputButton1"
        runat="server"
        type="button"
        onserverclick="HtmlInputButton1_ServerClick"
        value="Html Input Button"
        name="HtmlInputButton1">&nbsp;&nbsp;

      <DIV id="Div1" runat="server"
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px"
        ms_positioning="FlowLayout" />
    </form>
  </body>
</HTML>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL.Controls" Assembly="Samples.AspNet.JSL" %>
<%@ Page Language="VJ#" AutoEventWireup="True" %>
<HTML>
  <HEAD>
    <title>Custom HtmlInputButton - OnPreRender - VJ# Example</title>
    <script runat="server">
    void Page_Load(Object sender, EventArgs e)
    {
        HtmlInputButton1.get_Attributes().Add("onclick",
            "alert('Hello client-side world.');");
    } //Page_Load

    void HtmlInputButton1_ServerClick(Object sender, EventArgs e)
    {
        Div1.set_InnerHtml("Hello server-side world.");
    } //HtmlInputButton1_ServerClick
    </script>
  </HEAD>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom HtmlInputButton - OnPreRender - VJ# Example</h3>

      <aspSample:CustomHtmlInputButtonOnPreRender
        id="HtmlInputButton1"
        runat="server"
        type="button"
        onserverclick="HtmlInputButton1_ServerClick"
        value="Html Input Button"
        name="HtmlInputButton1">&nbsp;&nbsp;

      <DIV id="Div1" runat="server"
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px"
        ms_positioning="FlowLayout" />
    </form>
  </body>
</HTML>

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls

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

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

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

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

End Namespace

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlInputButtonOnPreRender : System.Web.UI.HtmlControls.HtmlInputButton
    {
        protected override void OnPreRender(System.EventArgs e)
        {
            // Call the base class's OnPreRender method.
            base.OnPreRender(e);

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

package Samples.AspNet.JSL.Controls;

public class CustomHtmlInputButtonOnPreRender
    extends System.Web.UI.HtmlControls.HtmlInputButton
{
    protected void OnPreRender(System.EventArgs e)
    {
        // Call the base OnPreRender method.
        super.OnPreRender(e);
        // Always display the HtmlButton with bold text.
        this.get_Style().Add("font-weight", "bold");
    } //OnPreRender
} //CustomHtmlInputButtonOnPreRender

Plattformen

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

HtmlInputButton-Klasse
HtmlInputButton-Member
System.Web.UI.HtmlControls-Namespace

Weitere Ressourcen

HTML-Serversteuerelemente

Last updated on 2007-08-20

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