AttributeCollection.Render-Methode

Schreibt die Auflistung der Attribute in den angegebenen HtmlTextWriter-Ausgabestream. Der Ausgabestream schreibt die Auflistung wiederum in das ASP.NET-Serversteuerelement, zu dem die Auflistung gehört.

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

Syntax

'Declaration
Public Sub Render ( _
    writer As HtmlTextWriter _
)
'Usage
Dim instance As AttributeCollection
Dim writer As HtmlTextWriter

instance.Render(writer)

public void Render (
    HtmlTextWriter writer
)

public:
void Render (
    HtmlTextWriter^ writer
)

public void Render (
    HtmlTextWriter writer
)

public function Render (
    writer : HtmlTextWriter
)

Parameter

• writer
  Ein HtmlTextWriter-Objekt, das die Attributauflistung in die aktuelle Ausgabestreamposition schreibt.

Beispiel

Dieser Abschnitt enthält zwei Codebeispiele. Im folgenden Codebeispiel wird veranschaulicht, wie durch Vererben der WebControl-Klasse ein benutzerdefiniertes Steuerelement mit der Bezeichnung AttribRender erstellt wird, das die Render-Methode überschreibt. Im folgenden Codebeispiel wird die Verwendung des benutzerdefinierten Steuerelements auf einer ASP.NET-Webseite veranschaulicht. Im Codebeispiel wird davon ausgegangen, dass sich die Codedatei für das benutzerdefinierte Steuerelement im Ordner App_Code der Anwendung befindet.

Im folgenden Codebeispiel wird das Erstellen eines benutzerdefinierten Steuerelements mit der Bezeichnung AttribRender veranschaulicht, das die Render-Methode der WebControl-Klasse ohne Aufrufen der Render-Methode für die Basisklasse überschreibt. AttribRender ruft stattdessen die Render-Methode auf.

' Create a custom WebControl class, named AttribRender, that overrides 
' the Render method to write two introductory strings. Then call the
' AttributeCollection.Render method, which allows the control to write the
' attribute values that are added to it when it is included in a page.
Imports System
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Security.Permissions

' Create the namespace that contains the AttribRender and the
' page that accesses it.
Namespace AC_Render

 ' This is the custom WebControl class.
    <AspNetHostingPermission(SecurityAction.Demand, _
      Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public Class AttribRender
        Inherits WebControl

        ' This is the overridden WebControl.Render method.
        Protected Overrides Sub Render(ByVal output As HtmlTextWriter)
            output.Write("<h2>An AttributeCollection.Render Method Example</h2>")
            output.Write("The attributes, and their values, added to the ctl1 control are <br><br>")
            ' This is the AttributeCollection.Render method call. When the
            ' page that contains this control is requested, the
            ' attributes that the page adds, and their values,
            ' are rendered to the page.
            Attributes.Render(output)
        End Sub 'Render
    End Class 'AttribRender

End Namespace 'AC_Render

/* Create a custom WebControl class, named AttribRender, that overrides 
   the Render method to write two introductory strings. Then call the
   AttributeCollection.Render method, which allows the control to write the
   attribute values that are added to it when it is included in a page.
*/
   
using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Permissions;

// Create the namespace that contains the AttribRender and the
// page that accesses it.
namespace AC_Render
{
   // This is the custom WebControl class.
   [AspNetHostingPermission(SecurityAction.Demand, 
      Level=AspNetHostingPermissionLevel.Minimal)]
   public class AttribRender : WebControl
   {
      // This is the overridden WebControl.Render method.
      protected override void Render(HtmlTextWriter output)
      {
         output.Write("<h2>An AttributeCollection.Render Method Example</h2>");
         output.Write("The attributes, and their values, added to the ctl1 control are <br><br>");
         // This is the AttributeCollection.Render method call. When the
         // page that contains this control is requested, the
         // attributes that the page adds, and their values,
         // are rendered to the page.
         Attributes.Render(output);
      }
   }
}

/* Create a custom WebControl class, named AttribRender, that overrides 
   the Render method to write two introductory strings. Then call the
   AttributeCollection.Render method, which allows the control to write the
   attribute values that are added to it when it is included in a page.
   This sample can be used as a code-behind file for a.aspx file.
*/

// Create the package that contains the AttribRender and the
// page that accesses it.
package AC_Render; 

import System.*;
import System.Web.UI.*;
import System.Web.UI.WebControls.*;
   
// This is the custom WebControl class.
public class AttribRender extends WebControl
{
    // This is the overridden WebControl.Render method.
    protected void Render(HtmlTextWriter output)
    {
        output.Write("<h2>An AttributeCollection.Render Method Example</h2>");
        output.Write("The attributes, and their values, added to the ctl1 "
            + "control are <br><br>");

        // This is the AttributeCollection.Render method call. When the
        // page that contains this control is requested, the
        // attributes that the page adds, and their values,
        // are rendered to the page.
        get_Attributes().Render(output);
    } //Render
} //AttribRender   
   

Im folgenden Codebeispiel wird die Verwendung des benutzerdefinierten Steuerelements AttribRender auf einer Webseite veranschaulicht. Dabei wird davon ausgegangen, dass sich die Codedatei für das benutzerdefinierte Steuerelement im Ordner App_Code der Anwendung befindet.

<%@ Page Language="VB"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

    Dim c As New AC_Render.AttribRender()
    c.Attributes.Add("Text", "Hello World!")
    c.Attributes.Add("Attribute1", "The value for Attribute1.")
    Place1.Controls.Add(c)

  End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>AttributeCollection Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <asp:PlaceHolder id="Place1" runat="server"></asp:PlaceHolder>
    </div>
    </form>
</body>
</html>

<%@ Page Language="C#"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  protected void Page_Load(object sender, EventArgs e)
  {
    AC_Render.AttribRender c = new AC_Render.AttribRender();
    c.Attributes.Add("Text", "Hello World!");
    c.Attributes.Add("Attribute1", "The value for Attribute1.");
    Place1.Controls.Add(c);
    
  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>AttributeCollection Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <asp:PlaceHolder id="Place1" runat="server"></asp:PlaceHolder>
    </div>
    </form>
</body>
</html>

<%@ Page Language="VJ#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  protected void Page_Load(Object sender, EventArgs e)
  {
    AC_Render.AttribRender c = new AC_Render.AttribRender();
    c.get_Attributes().Add("Text", "HelloWorld!");
    c.get_Attributes().Add("Attribute1", "The value for Attribute1.");
    get_Controls().Add(c);

  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>AttributeCollection Example</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <asp:PlaceHolder id="Place1" runat="server"></asp:PlaceHolder>
    </div>
    </form>
</body>
</html>

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

AttributeCollection-Klasse
AttributeCollection-Member
System.Web.UI-Namespace
Attributes
HtmlTextWriter
Attributes