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HtmlTextArea.RenderAttributes(HtmlTextWriter) Methode

  • Referenz

Definition

Namespace:
System.Web.UI.HtmlControls
Assembly:
System.Web.dll

Rendert die Attribute des HtmlTextArea-Steuerelements in das angegebene HtmlTextWriter-Objekt.

protected:
 override void RenderAttributes(System::Web::UI::HtmlTextWriter ^ writer);
protected override void RenderAttributes (System.Web.UI.HtmlTextWriter writer);
override this.RenderAttributes : System.Web.UI.HtmlTextWriter -> unit
Protected Overrides Sub RenderAttributes (writer As HtmlTextWriter)

Parameter

writer
HtmlTextWriter

Der HtmlTextWriter, der den gerenderten Inhalt empfängt.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die RenderAttributes Methode in einem benutzerdefinierten Serversteuerelement überschreiben, sodass für das HtmlTextArea Steuerelement immer bestimmte Titeltext 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">
<script runat="server">
  
  void Page_Load(Object sender, EventArgs e)
  {
    HtmlTextArea1.Value = "Hello HTML Text Area World.";
  }
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>Custom HtmlTextArea RenderAttributes Example</title>
  </head>

  <body>
    <form id="Form1" 
          method="post" 
          runat="server">

      <h3>Custom HtmlTextArea - RenderAttributes - C# Example</h3>

      <aspSample:CustomHtmlTextAreaRenderAttributes 
        id="HtmlTextArea1" 
        name="HtmlTextArea1" 
        runat="server" 
        rows="4" 
        cols="50" />
        
    </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">
<script runat="server">

  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    
    HtmlTextArea1.Value = "Hello HTML Text Area World."
    
  End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head>
    <title>Custom HtmlTextArea RenderAttributes Example</title>
  </head>

  <body>
    <form id="Form1" 
          method="post"
          runat="server">

      <h3>Custom HtmlTextArea RenderAttributes Example</h3>

      <aspSample:CustomHtmlTextAreaRenderAttributes 
        id="HtmlTextArea1" 
        name="HtmlTextArea1" 
        runat="server" 
        rows="4" 
        cols="50" />
        
    </form>
  </body>
</html>

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

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlTextAreaRenderAttributes : System.Web.UI.HtmlControls.HtmlTextArea
    {
        protected override void RenderAttributes(System.Web.UI.HtmlTextWriter writer)
        {
            // Write out the Title attribute.
            writer.Write(" Title=\"Text from RenderAttributes.\"");
            
            // Call the base class's RenderAttributes method.
            base.RenderAttributes(writer);
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomHtmlTextAreaRenderAttributes
        Inherits System.Web.UI.HtmlControls.HtmlTextArea

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

            ' Write out the Title attribute.
            writer.Write(" Title=""Text from RenderAttributes.""")

            ' Call the base class's RenderAttributes method.
            MyBase.RenderAttributes(writer)
        End Sub
    End Class
End Namespace

Hinweise

Die RenderAttributes Methode rendert das name Attribut des HtmlTextArea Steuerelements direkt, um sicherzustellen, dass es denselben Wert wie die Control.UniqueID Eigenschaft hat. Nach dem Rendern des Attributs RenderAttributes ruft die RenderAttributes Methode der Basisklasse auf.

Die RenderAttributes Methode wird hauptsächlich von Steuerelemententwicklern verwendet, die die Funktionalität des HtmlTextArea Steuerelements erweitern.

Gilt für

Siehe auch