HtmlInputRadioButton.RenderAttributes(HtmlTextWriter) Metodo

Riferimento

Definizione

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

Assembly:: System.Web.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Esegue il rendering degli attributi del controllo HtmlInputRadioButton sull'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 che riceve l'output di cui è stato eseguito il rendering.

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 venga sempre visualizzato per .HtmlInputRadioButton

<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Samples" Assembly="Samples.AspNet.CS" %>
<!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 HtmlInputRadioButton - RenderAttributes - C# Example</title>
    <script runat="server">
      void Page_Load(Object sender, EventArgs e) 
      {
        Div1.InnerHtml = "";
      }

      void HtmlInputRadioButtonGroup1_ServerChange(object sender, System.EventArgs e)
      {
        // Diplay the value of the selected HtmlInputRadioButton control.
        System.Web.UI.HtmlControls.HtmlInputRadioButton htmlInputRadioButtonGroup1 = (System.Web.UI.HtmlControls.HtmlInputRadioButton) sender;
        Div1.InnerHtml = "You change your selection to: " + htmlInputRadioButtonGroup1.Value;
      }
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom HtmlInputRadioButton - Method - C# RenderAttributes</h3>

      <aspSample:CustomHtmlInputRadioButtonRenderAttributes 
        id="HtmlInputRadioButton1" 
        name="HtmlInputRadioButtonGroup1" 
        runat="server" 
        type="radio" checked
        onserverchange="HtmlInputRadioButtonGroup1_ServerChange" 
        value="HtmlInputRadioButton1">HtmlInputRadioButton1
      </aspSample:CustomHtmlInputRadioButtonRenderAttributes>
      <br />

      <aspSample:CustomHtmlInputRadioButtonRenderAttributes 
        id="HtmlInputRadioButton2" 
        name="HtmlInputRadioButtonGroup1" 
        runat="server" 
        type="radio" 
        onserverchange="HtmlInputRadioButtonGroup1_ServerChange" 
        value="HtmlInputRadioButton2">HtmlInputRadioButton2
      </aspSample:CustomHtmlInputRadioButtonRenderAttributes><br />

      <p>
        <input type="submit" value="Submit" id="Submit1" name="Submit1" runat="server" />
      </p>
      
      <div 
        id="Div1" 
        runat="server" 
        style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
    </form>
  </body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Samples" Assembly="Samples.AspNet.VB" %>
<!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 HtmlInputRadioButton - RenderAttributes - Visual Basic Example</title>
    <script runat="server">
      Sub Page_Load(sender As Object, e As EventArgs)
        Div1.InnerHtml = ""
      End Sub

      Sub HtmlInputRadioButtonGroup1_ServerChange(sender As Object, e As System.EventArgs)
        Dim htmlInputRadioButtonGroup1 As System.Web.UI.HtmlControls.HtmlInputRadioButton  = CType(sender, System.Web.UI.HtmlControls.HtmlInputRadioButton)
        Div1.InnerHtml = "You change your selection to: " & htmlInputRadioButtonGroup1.Value
      End Sub
    </script>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom HtmlInputRadioButton - Method - Visual Basic RenderAttributes</h3>

      <aspSample:CustomHtmlInputRadioButtonRenderAttributes 
        id="HtmlInputRadioButton1" 
        name="HtmlInputRadioButtonGroup1" 
        runat="server" 
        type="radio" checked
        onserverchange="HtmlInputRadioButtonGroup1_ServerChange" 
        value="HtmlInputRadioButton1">HtmlInputRadioButton1
      </aspSample:CustomHtmlInputRadioButtonRenderAttributes>
      <br />

      <aspSample:CustomHtmlInputRadioButtonRenderAttributes 
        id="HtmlInputRadioButton2" 
        name="HtmlInputRadioButtonGroup1" 
        runat="server" 
        type="radio" 
        onserverchange="HtmlInputRadioButtonGroup1_ServerChange" 
        value="HtmlInputRadioButton2">HtmlInputRadioButton2
      </aspSample:CustomHtmlInputRadioButtonRenderAttributes><br />

      <p>
        <input type="submit" value="Submit" id="Submit1" name="Submit1" runat="server" />
      </p>
      
      <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.Samples
{
    [AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
    public sealed class CustomHtmlInputRadioButtonRenderAttributes : System.Web.UI.HtmlControls.HtmlInputRadioButton
    {
        protected override void RenderAttributes(System.Web.UI.HtmlTextWriter writer)
        {
            
            // Call the base class's RenderAttributes method.
            base.RenderAttributes(writer);

            // Write out the control's Title tag.
            writer.Write(" Title=\"Option " + this.Value + "\"");
        }
    }
}


Imports System.Web
Imports System.Security.Permissions

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

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

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

            ' Write out the control's Title tag.
            writer.Write((" Title=""Option " + Me.Value + """"))

        End Sub
    End Class
End Namespace

Commenti

Il RenderAttributes metodo scrive la Value proprietà come attributo del HtmlInputRadioButton controllo e quindi chiama il metodo della RenderAttributes classe base

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

Si applica a

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