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HtmlTextArea.RenderAttributes(HtmlTextWriter) Method

  • Reference

Definition

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

Renders the HtmlTextArea control's attributes to the specified HtmlTextWriter object.

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)

Parameters

writer
HtmlTextWriter

The HtmlTextWriter that receives the rendered content.

Examples

The following code example demonstrates how to override the RenderAttributes method in a custom server control so that specific title text is always displayed for the HtmlTextArea control.

<%@ 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

Remarks

The RenderAttributes method renders the name attribute of the HtmlTextArea control directly to ensure that it has the same value as the Control.UniqueID property. After rendering the attribute, the RenderAttributes method calls the base class's RenderAttributes method.

The RenderAttributes method is used primarily by control developers extending the functionality of the HtmlTextArea control.

Applies to

See also