RadioButtonList.Render(HtmlTextWriter) Metodo

  • Riferimento

Definizione

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

Visualizza il controllo RadioButtonList nel client.

protected:
 override void Render(System::Web::UI::HtmlTextWriter ^ writer);
protected public:
 override void Render(System::Web::UI::HtmlTextWriter ^ writer);
protected override void Render (System.Web.UI.HtmlTextWriter writer);
protected internal override void Render (System.Web.UI.HtmlTextWriter writer);
override this.Render : System.Web.UI.HtmlTextWriter -> unit
Protected Overrides Sub Render (writer As HtmlTextWriter)
Protected Friend Overrides Sub Render (writer As HtmlTextWriter)

Parametri

writer
HtmlTextWriter

Oggetto HtmlTextWriter che contiene il flusso di output per il rendering nel client.

Esempio

Nell'esempio di codice seguente viene illustrato come eseguire l'override del Render metodo in un controllo server personalizzato in modo che il RadioButtonList controllo venga sempre visualizzato con testo descrittivo.

<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" 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 RadioButtonList - Render - C# Example</title>
  </head>
  <body>
    <form id="Form1" method="post" runat="server">
      <h3>Custom RadioButtonList - Render - C# Example</h3>

      <aspSample:CustomRadioButtonListRender 
        id="Radiobuttonlist1" 
        runat="server" 
        RepeatColumns="2" 
        RepeatDirection="Horizontal">
        <asp:ListItem Value="Item1">Item1</asp:ListItem>
        <asp:ListItem Value="Item2">Item2</asp:ListItem>
        <asp:ListItem Value="Item3">Item3</asp:ListItem>
        <asp:ListItem Value="Item4">Item4</asp:ListItem>
      </aspSample:CustomRadioButtonListRender>
      
    </form>
  </body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" 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 RadioButtonList - Render - VB.NET Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom RadioButtonList - Render - VB.NET Example</h3>

            <aspSample:CustomRadioButtonListRender
             id="Radiobuttonlist1" runat="server" 
             RepeatColumns="2" RepeatDirection="Horizontal">
                <asp:ListItem Value="Item1">Item1</asp:ListItem>
                <asp:ListItem Value="Item2">Item2</asp:ListItem>
                <asp:ListItem Value="Item3">Item3</asp:ListItem>
                <asp:ListItem Value="Item4">Item4</asp:ListItem>
            </aspSample:CustomRadioButtonListRender>
        </form>
    </body>
</html>

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

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomRadioButtonListRender : System.Web.UI.WebControls.RadioButtonList
  {
    protected override void Render(System.Web.UI.HtmlTextWriter writer)
    {
      // Call the base RenderContents method.
      base.Render(writer);

      // Append some text to the Image.
      writer.Write("Experience Windows Server 2003 and Visual Studio® .NET 2003.");
    }
  }
}

Imports System.Web
Imports System.Security.Permissions

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

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

            ' Call the base RenderContents method.
            MyBase.Render(writer)

            ' Append some text to the Image.
            writer.Write("Experience Windows Server 2003 and Visual Studio .NET 2003.")
        End Sub
    End Class
End Namespace

Commenti

Questo metodo viene usato principalmente dagli sviluppatori di controlli nei controlli personalizzati che derivano dalla RadioButtonList classe .

L'implementazione Render del metodo per un RadioButtonList controllo inizializza un RepeatInfo oggetto per l'elenco e chiama il RenderRepeater metodo , che a sua volta usa il metodo per eseguire il RenderItem rendering di singoli elementi dell'elenco dei pulsanti di opzione.

Si applica a

Vedi anche