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ListBox.AddAttributesToRender-Methode

  • Artikel

Diese Methode unterstützt die .NET Framework-Infrastruktur und ist nicht für die direkte Verwendung in Code bestimmt.

Fügt der Liste wiederzugebender Attribute name, size, multiple und onchange hinzu.

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

Syntax

'Declaration
Protected Overrides Sub AddAttributesToRender ( _
    writer As HtmlTextWriter _
)
'Usage
Dim writer As HtmlTextWriter

Me.AddAttributesToRender(writer)

protected override void AddAttributesToRender (
    HtmlTextWriter writer
)

protected:
virtual void AddAttributesToRender (
    HtmlTextWriter^ writer
) override

protected void AddAttributesToRender (
    HtmlTextWriter writer
)

protected override function AddAttributesToRender (
    writer : HtmlTextWriter
)

Parameter

  • writer
    Der Ausgabestream, der HTML-Inhalt für den Client wiedergibt.

Beispiel

Im folgenden Codebeispiel wird das Überschreiben der AddAttributesToRender-Methode in einem benutzerdefinierten Serversteuerelement veranschaulicht, sodass der ListBox-Listenelementtext immer fett angezeigt wird.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom ListBox - AddAttributesToRender -  VB.NET Example</title>
        <script runat="server">
            Sub Page_Load(sender As Object, e As EventArgs)
                ListBox1.Items.Add(New ListItem("Item1", "Item1"))
                ListBox1.Items.Add(New ListItem("Item2", "Item2"))
                ListBox1.Items.Add(New ListItem("Item2", "Item2"))
            End Sub
        </script>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom ListBox - AddAttributesToRender - VB.NET Example</h3>
            
            <aspSample:CustomListBoxAddAttributesToRender id="ListBox1" runat="server" />
        </form>
    </body>
</HTML>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom ListBox - AddAttributesToRender - C# Example</title>
    <script runat="server">
          private void Page_Load(object sender, System.EventArgs e)
      {
        ListBox1.Items.Add(new ListItem("Item1", "Item1"));
        ListBox1.Items.Add(new ListItem("Item2", "Item2"));
        ListBox1.Items.Add(new ListItem("Item2", "Item2"));
      }
    </script>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom ListBox - AddAttributesToRender - C# Example</h3>
            
            <aspSample:CustomListBoxAddAttributesToRender 
              id="ListBox1" 
              runat="server" />
              
        </form>
    </body>
</HTML>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL.Controls" Assembly="Samples.AspNet.JSL" %>
<%@ Page Language="VJ#" AutoEventWireup="True" %>
<HTML>
    <HEAD>
        <title>Custom ListBox - AddAttributesToRender - VJ# Example</title>
    <script runat="server">
        private void Page_Load(Object sender, System.EventArgs e)
        {
            ListBox1.get_Items().Add(new ListItem("Item1", "Item1"));
            ListBox1.get_Items().Add(new ListItem("Item2", "Item2"));
            ListBox1.get_Items().Add(new ListItem("Item2", "Item2"));
        } //Page_Load
    </script>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom ListBox - AddAttributesToRender - VJ# Example</h3>
            
            <aspSample:CustomListBoxAddAttributesToRender 
              id="ListBox1" 
              runat="server" />
              
        </form>
    </body>
</HTML>

<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomListBoxAddAttributesToRender
    Inherits System.Web.UI.WebControls.ListBox

    Protected Overrides Sub AddAttributesToRender(ByVal writer As System.Web.UI.HtmlTextWriter)

        ' Show the ListItem text as Bold 
        writer.AddStyleAttribute(System.Web.UI.HtmlTextWriterStyle.FontWeight, "bold")

        ' Call the Base's AddAttributesToRender method.
        MyBase.AddAttributesToRender(writer)
    End Sub
End Class

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

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomListBoxAddAttributesToRender : System.Web.UI.WebControls.ListBox
  {
    protected override void AddAttributesToRender(System.Web.UI.HtmlTextWriter writer)
    {
      // Show the ListItem text as Bold 
      writer.AddStyleAttribute(System.Web.UI.HtmlTextWriterStyle.FontWeight, "bold");

      // Call the Base's AddAttributesToRender method.
      base.AddAttributesToRender(writer);
    }
  }
}

package Samples.AspNet.JSL.Controls; 

public class CustomListBoxAddAttributesToRender
    extends System.Web.UI.WebControls.ListBox
{
    protected void AddAttributesToRender(System.Web.UI.HtmlTextWriter writer)
    {
        // Show the ListItem text as Bold 
        writer.AddStyleAttribute(System.Web.UI.HtmlTextWriterStyle.FontWeight, 
            "bold");
        // Call the Base's AddAttributesToRender method.
        super.AddAttributesToRender(writer);
    } //AddAttributesToRender
} //CustomListBoxAddAttributesToRender

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

ListBox-Klasse
ListBox-Member
System.Web.UI.WebControls-Namespace

Weitere Ressourcen

ListBox-Webserver-Steuerelement