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WebControl.AddAttributesToRender Method

Adds HTML attributes and styles that need to be rendered to the specified HtmlTextWriterTag. This method is used primarily by control developers.

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

protected virtual void AddAttributesToRender(
	HtmlTextWriter writer
)

Parameters

writer
Type: System.Web.UI.HtmlTextWriter

A HtmlTextWriter that represents the output stream to render HTML content on the client.

To render attributes and styles for a Web Server control on the client, you typically call the AddAttribute and HtmlTextWriter.AddStyleAttribute methods to insert each attribute and style individually to the HtmlTextWriter output stream. To simplify the process, this method encapsulates all calls to the HtmlTextWriter.AddAttribute and HtmlTextWriter.AddStyleAttribute methods for every attribute and style associated with the Web server control. All attributes and styles are inserted into the HtmlTextWriter output stream in a single method call. This method is typically overridden by control developers in derived classes to insert the appropriate attributes and styles to the HtmlTextWriter output stream for the class.

NoteNote:

The AddAttributesToRender method cannot be used to insert client script. To use client script, see the ClientScriptManager class.

The following example demonstrates how to create a class that derives from the WebControl class. The base implementation of the AddAttributesToRender method is overridden to add attributes appropriate to the derived class in the HtmlTextWriter output stream.

namespace ControlTest 
{
   using System;
   using System.Web.UI;
   using System.Web.UI.WebControls;

   // Renders the following HTML:  
   // <span onclick="alert('Hello');" style="color:Red;">Custom Contents</span>

   public class MyWebControl: WebControl {

      public MyWebControl() : base(HtmlTextWriterTag.Span) 
      { }

      [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
      protected override void AddAttributesToRender(HtmlTextWriter writer) 
      {

         writer.AddAttribute(HtmlTextWriterAttribute.Onclick, "alert('Hello');");
         writer.AddStyleAttribute(HtmlTextWriterStyle.Color, "Red");
         base.AddAttributesToRender(writer);

      }

      [System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name="FullTrust")] 
      protected override void RenderContents(HtmlTextWriter writer) 
      {
         writer.Write("Custom Contents");
         base.RenderContents(writer);
      }
   }
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

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