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Image.RenderContents(HtmlTextWriter) Metodo

Definizione

Esegue il rendering del contenuto del controllo immagine nel writer specificato.

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

Parametri

writer
HtmlTextWriter

Oggetto HtmlTextWriter che rappresenta il flusso di output per il rendering del contenuto HTML nel client.

Esempio

Nell'esempio di codice seguente viene illustrato come eseguire l'override del RenderContents metodo in un controllo server personalizzato in modo che un testo venga sempre visualizzato dopo .Image

<%@ 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 Image - RenderContents - C# Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom Image - RenderContents - C# Example</h3>
            
            <aspSample:CustomImageRenderContents 
              id="Image1" 
              runat="server" 
              ImageUrl="http://www.microsoft.com/homepage/gif/bnr-microsoft.gif" 
              AlternateText="Microsoft Home" />
            
        </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 Image - RenderContents - VB.NET Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom Image - RenderContents - VB.NET Example</h3>
            
            <aspSample:CustomImageRenderContents id="Image1" runat="server" 
             ImageUrl="http://www.microsoft.com/homepage/gif/bnr-microsoft.gif" 
             AlternateText="Microsoft Home" />
            
        </form>
    </body>
</html>
using System.Web;
using System.Security.Permissions;

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

      // Append some text to the Image.
      writer.Write("<BR>Experience Windows Server 2003 and Visual Studio® .NET 2003.");
    }
  }
}
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomImageRenderContents
    Inherits System.Web.UI.WebControls.Image

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

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

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

Commenti

Il RenderContents metodo viene usato principalmente dagli sviluppatori di controlli. Il Image controllo implementa il metodo per ignorare il RenderContents rendering di tutti i controlli figlio.

Si applica a

Vedi anche