Muokkaa

Jaa

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);
protected override void AddAttributesToRender (System.Web.UI.HtmlTextWriter writer);
override this.AddAttributesToRender : System.Web.UI.HtmlTextWriter -> unit
Protected Overrides Sub AddAttributesToRender (writer As HtmlTextWriter)

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>

<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
    <head>
        <title>Custom ListBox - AddAttributesToRender -  VB.NET Example</title>
        <script runat="server">
            Sub Page_Load(sender As Object, e As EventArgs)
                ListBox1.Items.Add(New ListItem("Item1", "Item1"))
                ListBox1.Items.Add(New ListItem("Item2", "Item2"))
                ListBox1.Items.Add(New ListItem("Item2", "Item2"))
            End Sub
        </script>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom ListBox - AddAttributesToRender - VB.NET 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);
    }
  }
}

<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomListBoxAddAttributesToRender
    Inherits System.Web.UI.WebControls.ListBox

    Protected Overrides Sub AddAttributesToRender(ByVal writer As System.Web.UI.HtmlTextWriter)

        ' Show the ListItem text as Bold 
        writer.AddStyleAttribute(System.Web.UI.HtmlTextWriterStyle.FontWeight, "bold")

        ' Call the Base's AddAttributesToRender method.
        MyBase.AddAttributesToRender(writer)
    End Sub
End Class

Applies to

See also