OpenWriteCompletedEventHandler OpenWriteCompletedEventHandler OpenWriteCompletedEventHandler OpenWriteCompletedEventHandler Delegate

Définition

Représente la méthode qui gérera l'événement OpenWriteCompleted d'un WebClient.Represents the method that will handle the OpenWriteCompleted event of a WebClient.

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

Paramètres

sender
Object Object Object Object

Source de l'événement.The source of the event.

Héritage
OpenWriteCompletedEventHandlerOpenWriteCompletedEventHandlerOpenWriteCompletedEventHandlerOpenWriteCompletedEventHandler

Exemples

L’exemple de code suivant illustre l’ouverture d’un flux pour écrire des données à charger.The following code example demonstrates opening a stream to write data to be uploaded.

void OpenResourceForPosting( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);
   
   // Specify that the OpenWriteCallback method gets called
   // when the writeable stream is available.
   client->OpenWriteCompleted += gcnew OpenWriteCompletedEventHandler( OpenWriteCallback2 );
   client->OpenWriteAsync( uri );
   
   // Applications can perform other tasks
   // while waiting for the upload to complete.
}


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

    // Specify that the OpenWriteCallback method gets called
    // when the writeable stream is available.
    client.OpenWriteCompleted += new OpenWriteCompletedEventHandler (OpenWriteCallback2);
    client.OpenWriteAsync (uri);
    // Applications can perform other tasks
    // while waiting for the upload to complete.
}

Public Shared Sub OpenResourceForPosting(ByVal address As String)

	Dim client As WebClient = New WebClient()
	'  Specify that the OpenWriteCallback method gets called
	'  when the writeable stream is available.
	AddHandler client.OpenWriteCompleted, AddressOf OpenWriteCallback2
                      Dim uri as Uri = New Uri(address)
	client.OpenWriteAsync(uri)
	'  Applications can perform other tasks
	'  while waiting for the upload to complete.
End Sub

La méthode suivante est appelée lorsque le flux est disponible.The following method is called when the stream is available.

void OpenWriteCallback2( Object^ /*sender*/, OpenWriteCompletedEventArgs^ e )
{
   Stream^ body = nullptr;
   StreamWriter^ s = nullptr;
   try
   {
      body = dynamic_cast<Stream^>(e->Result);
      s = gcnew StreamWriter( body );
      s->AutoFlush = true;
      s->Write( "This is content data to be sent to the server." );
   }
   finally
   {
      if ( s != nullptr )
      {
         s->Close();
      }
      if ( body != nullptr )
      {
         body->Close();
      }
   }

}


private static void OpenWriteCallback2 (Object sender, OpenWriteCompletedEventArgs e)
{
    Stream body = null;
    StreamWriter s = null;

    try
    {
        body = (Stream)e.Result;
        s = new StreamWriter (body);
        s.AutoFlush = true;
        s.Write ("This is content data to be sent to the server.");
    }
    finally
    {
        if (s != null)
        {
            s.Close ();
        }

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

Private Shared Sub OpenWriteCallback2(ByVal sender As Object, ByVal e As OpenWriteCompletedEventArgs)

    Dim body As Stream = Nothing
    Dim s As StreamWriter = Nothing

    Try

        body = CType(e.Result, Stream)
        s = New StreamWriter(body)
        s.AutoFlush = True
        s.Write("This is content data to be sent to the server.")
    Finally

        If Not s Is Nothing Then

            s.Close()
        End If

        If Not body Is Nothing Then

            body.Close()
        End If
    End Try
End Sub

Remarques

Lorsque vous créez un délégué OpenWriteCompletedEventHandler, vous identifiez la méthode qui gérera l'événement.When you create a OpenWriteCompletedEventHandler delegate, you identify the method that will handle the event. Pour associer l'événement au gestionnaire d'événements, ajoutez une instance du délégué à l'événement.To associate the event with your event handler, add an instance of the delegate to the event. Le gestionnaire d'événements est appelé chaque fois qu'un événement se produit, sauf si vous supprimez le délégué.The event handler is called whenever the event occurs, unless you remove the delegate.

Extension Methods

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

Obtient un objet qui représente la méthode représentée par le délégué spécifié.Gets an object that represents the method represented by the specified delegate.

S’applique à