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ListBox.AddAttributesToRender(HtmlTextWriter) Método

  • Referencia

Definición

Espacio de nombres:
System.Web.UI.WebControls
Ensamblado:
System.Web.dll

Agrega name, size, multiple y onchange a la lista de atributos para representar.

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)

Parámetros

writer
HtmlTextWriter

Flujo de salida que representa el contenido HTML en el cliente.

Ejemplos

En el ejemplo de código siguiente se muestra cómo invalidar el AddAttributesToRender método en un control de servidor personalizado, de modo que el texto del ListBox elemento de lista siempre se muestre como negrita.

<%@ 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

Se aplica a

Consulte también