.NET Framework Class Library
WebControlAddAttributesToRender 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)
Syntax
Protected Overridable Sub AddAttributesToRender ( _
	writer As [%$TOPIC/z029d2ky_en-us_VS_110_2_0_0_0_0%] _
)
protected virtual void AddAttributesToRender(
	[%$TOPIC/z029d2ky_en-us_VS_110_2_0_1_0_0%] writer
)
protected:
virtual void AddAttributesToRender(
	[%$TOPIC/z029d2ky_en-us_VS_110_2_0_2_0_0%]^ writer
)
abstract AddAttributesToRender : 
        writer:[%$TOPIC/z029d2ky_en-us_VS_110_2_0_3_0_0%] -> unit  
override AddAttributesToRender : 
        writer:[%$TOPIC/z029d2ky_en-us_VS_110_2_0_3_0_1%] -> unit

Parameters

writer
Type: System.Web.UIHtmlTextWriter

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

Remarks

To render attributes and styles for a Web Server control on the client, you typically call the AddAttribute and HtmlTextWriterAddStyleAttribute methods to insert each attribute and style individually to the HtmlTextWriter output stream. To simplify the process, this method encapsulates all calls to the HtmlTextWriterAddAttribute and HtmlTextWriterAddStyleAttribute 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.

Examples

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.

Imports System
Imports System.Web.UI
Imports System.Web.UI.WebControls

Namespace ControlTest

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


      Public Sub New()
         MyBase.New(HtmlTextWriterTag.Span)
      End Sub 'New      

      <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
      Protected Overrides Sub AddAttributesToRender(writer As HtmlTextWriter)

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

      End Sub 'AddAttributesToRender       

      <System.Security.Permissions.PermissionSetAttribute(System.Security.Permissions.SecurityAction.Demand, Name:="FullTrust")> _
      Protected Overrides Sub RenderContents(writer As HtmlTextWriter)
         writer.Write("Custom Contents")
         MyBase.RenderContents(writer)
      End Sub 'RenderContents

   End Class 'MyWebControl

End Namespace 'ControlTest
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);
      }
   }
}
Version Information

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0
Platforms

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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