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ListBox.AddAttributesToRender(HtmlTextWriter) Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Aggiunge name, size, multiple e onchange all'elenco di attributi di cui eseguire il rendering.

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)

Parametri

writer
HtmlTextWriter

Flusso di output che esegue il rendering del contenuto HTML nel client.

Esempio

Nell'esempio di codice seguente viene illustrato come eseguire l'override del metodo in un controllo server personalizzato, in modo che il AddAttributesToRender testo dell'elemento ListBox di elenco venga sempre visualizzato in grassetto.

<%@ 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

Si applica a

Vedi anche