TextBox.Render-Methode
Gibt das TextBox-Steuerelement im angegebenen HtmlTextWriter-Objekt wieder.
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)
Syntax
'Declaration
Protected Friend Overrides Sub Render ( _
writer As HtmlTextWriter _
)
'Usage
Dim writer As HtmlTextWriter
Me.Render(writer)
protected internal override void Render (
HtmlTextWriter writer
)
protected public:
virtual void Render (
HtmlTextWriter^ writer
) override
protected void Render (
HtmlTextWriter writer
)
protected internal override function Render (
writer : HtmlTextWriter
)
Parameter
- writer
Der HtmlTextWriter, der die wiedergegebene Ausgabe empfängt.
Hinweise
Die Render-Methode gibt das Anfangstag und das Endtag des TextBox-Steuerelements im HtmlTextWriter-Objekt für die Ausgabe auf dem Client wieder. Wenn die TextMode-Eigenschaft auf MultiLine festgelegt ist, wird der Inhalt des TextBox-Steuerelements als HTML-<textarea>-Element wiedergegeben.
Die Render-Methode wird hauptsächlich von Steuerelemententwicklern verwendet, um die Funktionalität des TextBox-Steuerelements zu erweitern.
Beispiel
Im folgenden Codebeispiel wird veranschaulicht, wie die Render-Methode in einem benutzerdefinierten Serversteuerelement überschrieben wird, sodass das TextBox-Steuerelement immer mit einem Bild angezeigt wird.
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<HTML>
<HEAD>
<title>Custom TextBox - Render - VB.NET Example</title>
</HEAD>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom TextBox - Render - VB.NET Example</h3>
<aspSample:CustomTextBoxRender id="TextBox1"
runat="server">Hello World!</aspSample:CustomTextBoxRender>
</form>
</body>
</HTML>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<HTML>
<HEAD>
<title>Custom TextBox - Render - C# Example</title>
</HEAD>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom TextBox - Render - C# Example</h3>
<aspSample:CustomTextBoxRender
id="TextBox1"
runat="server">Hello World!
</aspSample:CustomTextBoxRender>
</form>
</body>
</HTML>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL.Controls" Assembly="Samples.AspNet.JSL" %>
<%@ Page Language="VJ#" AutoEventWireup="True" %>
<HTML>
<HEAD>
<title>Custom TextBox - Render - VJ# Example</title>
</HEAD>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom TextBox - Render - VJ# Example</h3>
<aspSample:CustomTextBoxRender
id="TextBox1"
runat="server"
text="Hello World!">
</aspSample:CustomTextBoxRender>
</form>
</body>
</HTML>
Imports System.Web
Imports System.Security.Permissions
Namespace Samples.AspNet.VB.Controls
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomTextBoxRender
Inherits System.Web.UI.WebControls.TextBox
Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
' Create and render a new Image Web control.
Dim image As New System.Web.UI.WebControls.Image
image.ID = "Image1"
image.ImageUrl = "image.jpg"
image.AlternateText = "Image for TextBox1."
image.RenderControl(writer)
' Create a BR tag.
writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Br)
' Call the base class's Render method.
MyBase.Render(writer)
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 CustomTextBoxRender : System.Web.UI.WebControls.TextBox
{
protected override void Render(System.Web.UI.HtmlTextWriter writer)
{
// Create and render a new Image Web control.
System.Web.UI.WebControls.Image image = new System.Web.UI.WebControls.Image();
image.ID = "Image1";
image.ImageUrl = "image.jpg";
image.AlternateText = "Image for TextBox1.";
image.RenderControl(writer);
// Create a BR tag.
writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Br);
// Call the base class's Render method.
base.Render(writer);
}
}
}
package Samples.AspNet.JSL.Controls;
public class CustomTextBoxRender
extends System.Web.UI.WebControls.TextBox
{
protected void Render(System.Web.UI.HtmlTextWriter writer)
{
// Create and render a new Image Web control.
System.Web.UI.WebControls.Image image = new System.Web.UI.
WebControls.Image();
image.set_ID("Image1");
image.set_ImageUrl("image.jpg");
image.set_AlternateText("Image for TextBox1.");
image.RenderControl(writer);
// Create a BR tag.
writer.RenderBeginTag(System.Web.UI.HtmlTextWriterTag.Br);
// Call the base class's Render method.
super.Render(writer);
} //Render
} //CustomTextBoxRender
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
TextBox-Klasse
TextBox-Member
System.Web.UI.WebControls-Namespace
TextMode
RenderBeginTag
RenderEndTag