OpenReadCompletedEventHandler OpenReadCompletedEventHandler OpenReadCompletedEventHandler OpenReadCompletedEventHandler Delegate

Definition

Stellt die Methode zur Behandlung des OpenReadCompleted-Ereignisses eines WebClient-Objekts dar.Represents the method that will handle the OpenReadCompleted event of a WebClient.

public delegate void OpenReadCompletedEventHandler(System::Object ^ sender, OpenReadCompletedEventArgs ^ e);
public delegate void OpenReadCompletedEventHandler(object sender, OpenReadCompletedEventArgs e);
type OpenReadCompletedEventHandler = delegate of obj * OpenReadCompletedEventArgs -> unit
Public Delegate Sub OpenReadCompletedEventHandler(sender As Object, e As OpenReadCompletedEventArgs)

Parameter

sender
Object Object Object Object

Die Quelle des Ereignisses.The source of the event.

Vererbung
OpenReadCompletedEventHandlerOpenReadCompletedEventHandlerOpenReadCompletedEventHandlerOpenReadCompletedEventHandler

Beispiele

Im folgenden Codebeispiel veranschaulicht das Herunterladen einer Ressource zum Lesen.The following code example demonstrates downloading a resource for reading.

void OpenResourceForReading2( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);

   client->OpenReadCompleted += gcnew OpenReadCompletedEventHandler( OpenReadCallback2 );
   client->OpenReadAsync( uri );
}


public static void OpenResourceForReading2 (string address)
{
    WebClient client = new WebClient ();
    Uri uri = new Uri(address);

    client.OpenReadCompleted += new OpenReadCompletedEventHandler(OpenReadCallback2);
    client.OpenReadAsync (uri);
}

Public Shared Sub OpenResourceForReading2(ByVal address As String)

	Dim client As WebClient = New WebClient()
	AddHandler client.OpenReadCompleted, AddressOf OpenReadCallback2
                      Dim uri as Uri = New Uri(address)
	client.OpenReadAsync(uri)                        
End Sub

Die folgende Methode wird aufgerufen, wenn der Download abgeschlossen ist.The following method is called when the download completes.

void OpenReadCallback2( Object^ /*sender*/, OpenReadCompletedEventArgs^ e )
{
   Stream^ reply = nullptr;
   StreamReader^ s = nullptr;
   try
   {
      reply = dynamic_cast<Stream^>(e->Result);
      s = gcnew StreamReader( reply );
      Console::WriteLine( s->ReadToEnd() );
   }
   finally
   {
      if ( s != nullptr )
      {
         s->Close();
      }
      if ( reply != nullptr )
      {
         reply->Close();
      }
   }

}


private static void OpenReadCallback2 (Object sender, OpenReadCompletedEventArgs e)
{
    Stream reply = null;
    StreamReader s = null;

    try
    {
        reply = (Stream)e.Result;
        s = new StreamReader (reply);
        Console.WriteLine (s.ReadToEnd ());
    }
    finally
    {
        if (s != null)
        {
            s.Close ();
        }

        if (reply != null)
        {
            reply.Close ();
        }
    }
}

Private Shared Sub OpenReadCallback2(ByVal sender As Object, ByVal e As OpenReadCompletedEventArgs)

    Dim reply As Stream = Nothing
    Dim s As StreamReader = Nothing

    Try

        reply = CType(e.Result, Stream)
        s = New StreamReader(reply)
        Console.WriteLine(s.ReadToEnd())
    Finally

        If Not s Is Nothing Then

            s.Close()
        End If

        If Not reply Is Nothing Then

            reply.Close()
        End If
    End Try
End Sub

Hinweise

Beim Erstellen eines OpenReadCompletedEventHandler-Delegaten bestimmen Sie die Methode für die Ereignisbehandlung.When you create a OpenReadCompletedEventHandler delegate, you identify the method that will handle the event. Um dem Ereignishandler das Ereignis zuzuordnen, fügen Sie dem Ereignis eine Instanz des Delegaten hinzu.To associate the event with your event handler, add an instance of the delegate to the event. Der Ereignishandler wird bei jedem Eintreten des Ereignisses aufgerufen, sofern der Delegat nicht entfernt wird.The event handler is called whenever the event occurs, unless you remove the delegate.

Extension Methods

GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate) GetMethodInfo(Delegate)

Ruft ein Objekt, das die durch den angegebenen Delegaten dargestellte Methode darstellt.Gets an object that represents the method represented by the specified delegate.

Gilt für: