HtmlButton.OnPreRender(EventArgs) Méthode

  • Référence

Définition

Espace de noms:
System.Web.UI.HtmlControls
Assembly:
System.Web.dll

Déclenche l'événement PreRender et enregistre le script client pour générer une publication (postback).

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)

Paramètres

e
EventArgs

EventArgs qui contient les données d'événement.

Exemples

L’exemple de code suivant montre comment remplacer la OnPreRender méthode dans un contrôle serveur personnalisé afin qu’il affiche toujours le avec du HtmlButton texte en gras.

<%@ 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

Remarques

La OnPreRender méthode est principalement utilisée par les développeurs de contrôle qui étendent les fonctionnalités du HtmlButton contrôle.

S’applique à