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ListBox.AddAttributesToRender(HtmlTextWriter) Method

  • Reference

Definition

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

Adds name, size, multiple, and onchange to the list of attributes to render.

protected override void AddAttributesToRender(System.Web.UI.HtmlTextWriter writer);

Parameters

writer
HtmlTextWriter

The output stream that renders HTML content to the client.

Examples

The following code example demonstrates how to override the AddAttributesToRender method in a custom server control, so that the ListBox list item text always displays as bold.

<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
    <head>
        <title>Custom ListBox - AddAttributesToRender - C# Example</title>
    <script runat="server">
          private void Page_Load(object sender, System.EventArgs e)
      {
        ListBox1.Items.Add(new ListItem("Item1", "Item1"));
        ListBox1.Items.Add(new ListItem("Item2", "Item2"));
        ListBox1.Items.Add(new ListItem("Item2", "Item2"));
      }
    </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom ListBox - AddAttributesToRender - C# Example</h3>
            
            <aspSample:CustomListBoxAddAttributesToRender 
              id="ListBox1" 
              runat="server" />
              
        </form>
    </body>
</html>

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomListBoxAddAttributesToRender : System.Web.UI.WebControls.ListBox
  {
    protected override void AddAttributesToRender(System.Web.UI.HtmlTextWriter writer)
    {
      // Show the ListItem text as Bold 
      writer.AddStyleAttribute(System.Web.UI.HtmlTextWriterStyle.FontWeight, "bold");

      // Call the Base's AddAttributesToRender method.
      base.AddAttributesToRender(writer);
    }
  }
}

Applies to

Product Versions
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

See also