HtmlButton.RenderAttributes(HtmlTextWriter) Metodo

  • Riferimento

Definizione

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

Esegue il rendering degli attributi del controllo HtmlButton 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.

Esempio

Nell'esempio di codice seguente viene illustrato come eseguire l'override del RenderAttributes metodo in un controllo server personalizzato in modo che venga sempre visualizzato un titolo per il HtmlButton 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 HtmlButton - RenderAttributes - C# Example</title>
    <script runat="server">
      void Page_Load(Object sender, EventArgs e)
      {
        HtmlButton1.Attributes.Add("onclick","alert('Hello client-side world.');");
      }

      void HtmlButton1_ServerClick(Object sender, EventArgs e)
      {
        Div1.InnerHtml = "Hello server-side world.";
      }
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom HtmlButton - RenderAttributes - C# Example</h3>

      <aspSample:CustomHtmlButtonRenderAttributes
        id="HtmlButton1"
        runat="server"
        type="button"
        onserverclick="HtmlButton1_ServerClick"
        name="HtmlButton1">Html Button</aspSample:CustomHtmlButtonRenderAttributes>  

      <div id="Div1" runat="server"
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
    </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 HtmlButton - RenderAttributes - Visual Basic Example</title>
    <script runat="server">
      Sub Page_Load(sender As Object, e As EventArgs)
        HtmlButton1.Attributes.Add("onclick", "alert('Hello client-side world.');")
      End Sub

      Sub HtmlButton1_ServerClick(sender As Object, e As EventArgs)
        Div1.InnerHtml = "Hello server-side world."
      End Sub
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom HtmlButton - RenderAttributes - Visual Basic Example</h3>

      <aspSample:CustomHtmlButtonRenderAttributes
        id="HtmlButton1"
        runat="server"
        type="button"
        onserverclick="HtmlButton1_ServerClick"
        name="HtmlButton1">Html Button</aspSample:CustomHtmlButtonRenderAttributes>  

      <div id="Div1" runat="server"
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
    </form>
  </body>
</html>

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

namespace Samples.AspNet.CS.Controls
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlButtonRenderAttributes : System.Web.UI.HtmlControls.HtmlButton
    {
        protected override void RenderAttributes(System.Web.UI.HtmlTextWriter writer)
        {
            
            // Call the base class's RenderAttributes method.
            base.RenderAttributes(writer);

            // Write out the HtmlButton 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 CustomHtmlButtonRenderAttributes
        Inherits System.Web.UI.HtmlControls.HtmlButton

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

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

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

End Namespace

Commenti

Il RenderAttributes metodo scrive l'attributo onclick del controllo di cui è stato eseguito HtmlButton il rendering e quindi chiama il metodo di base HtmlControl.RenderAttributes .

Il RenderAttributes metodo viene usato principalmente dagli sviluppatori di controlli che estendono la funzionalità del HtmlButton controllo.

Si applica a

Vedi anche