HtmlAnchor.RenderAttributes(HtmlTextWriter) Metodo

  • Riferimento

Definizione

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

Esegue il rendering degli attributi del controllo HtmlAnchor nell'oggetto HtmlTextWriter specificato.

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)

Parametri

writer
HtmlTextWriter

Oggetto HtmlTextWriter contenente il flusso di output per il rendering sul client.

Eccezioni

HttpException

La proprietà HRef contiene un URL non valido.

Esempio

Nell'esempio di codice seguente viene illustrato come eseguire l'override del RenderAttributes metodo in un controllo server personalizzato in modo che il testo del titolo specifico, accessibile come descrizione comando, venga sempre visualizzato per il HtmlAnchor controllo.

<%@ 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 HtmlAnchor - RenderAttributes - C# Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      Top of Page
      <<aspSample:CustomHtmlAnchorRenderAttributes
           id="HtmlAnchor1"
           runat="server"
           name="HtmlAnchor1">HtmlAnchor1</aspSample:CustomHtmlAnchorRenderAttributes>>

      <h3>Custom HtmlAnchor - RenderAttributes - C# Example</h3>
      <p>Place the mouse pointer over the HtmlAnchor1 tag (above). A Title attribute was added from within the RenderAttributes override method.</p>
      <p>Jump to <a href="#HtmlAnchor2">HtmlAnchor2</a> below.</p>

      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>

      <p>Jump to <a href="#HtmlAnchor1">HtmlAnchor1</a> above.</p>
      <p> </p>Bottom of Page
      <<aspSample:CustomHtmlAnchorRenderAttributes
           id="HtmlAnchor2"
           runat="server"
           name="HtmlAnchor2">HtmlAnchor2</aspSample:CustomHtmlAnchorRenderAttributes>>
    </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 HtmlAnchor - RenderAttributes - Visual Basic Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      Top of Page
      <<aspSample:CustomHtmlAnchorRenderAttributes
           id="HtmlAnchor1"
           runat="server"
           name="HtmlAnchor1">HtmlAnchor1</aspSample:CustomHtmlAnchorRenderAttributes>>

      <h3>Custom HtmlAnchor - RenderAttributes - Visual Basic Example</h3>
      <p>Place the mouse pointer over the HtmlAnchor1 tag (above). A Title attribute was added from within the RenderAttributes override method.</p>
      <p>Jump to <a href="#HtmlAnchor2">HtmlAnchor2</a> below.</p>

      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>
      <p> </p><p> </p><p> </p><p> </p>

      <p>Jump to <a href="#HtmlAnchor1">HtmlAnchor1</a> above.</p>
      <p> </p>Bottom of Page
      <<aspSample:CustomHtmlAnchorRenderAttributes
           id="HtmlAnchor2"
           runat="server"
           name="HtmlAnchor2">HtmlAnchor2</aspSample:CustomHtmlAnchorRenderAttributes>>
    </form>
  </body>
</html>

using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlAnchorRenderAttributes : System.Web.UI.HtmlControls.HtmlAnchor
    {
        protected override void RenderAttributes(System.Web.UI.HtmlTextWriter writer)
        {
            // Call the base class's RenderAttributes method.
            base.RenderAttributes(writer);
            
            // Write out the HtmlAnchor control's Title tag.
            writer.Write(" Title=\"Text from RenderAttributes.\"");
        }
    }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomHtmlAnchorRenderAttributes
        Inherits System.Web.UI.HtmlControls.HtmlAnchor

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

            ' Call the base class's RenderAttributes method.
            MyBase.RenderAttributes(writer)

            ' Write out the HtmlAnchor control's Title tag.
            writer.Write(" Title=""Text from RenderAttributes.""")
        End Sub
    End Class
End Namespace

Commenti

Se il valore della HRef proprietà è un URL non valido, il RenderAttributes metodo genera un'eccezione HttpException .

Si applica a

Vedi anche