OpenWriteCompletedEventHandler Delegat

Definicja

Reprezentuje metodę, która będzie obsługiwać zdarzenie OpenWriteCompleted 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)

Parametry

sender
Object

Źródło zdarzenia.The source of the event.

e
OpenWriteCompletedEventArgs

OpenWriteCompletedEventArgs zawierający dane zdarzenia.A OpenWriteCompletedEventArgs containing event data.

Dziedziczenie
OpenWriteCompletedEventHandler

Przykłady

Poniższy przykład kodu demonstruje otwieranie strumienia w celu zapisania danych do przekazania.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

Następująca metoda jest wywoływana, gdy strumień jest dostępny.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

Uwagi

Podczas tworzenia delegata OpenWriteCompletedEventHandler należy zidentyfikować metodę, która będzie obsługiwać zdarzenie.When you create a OpenWriteCompletedEventHandler delegate, you identify the method that will handle the event. Aby skojarzyć zdarzenie z programem obsługi zdarzeń, Dodaj wystąpienie delegata do zdarzenia.To associate the event with your event handler, add an instance of the delegate to the event. Program obsługi zdarzeń jest wywoływany przy każdym wystąpieniu zdarzenia, o ile nie usunięto delegata.The event handler is called whenever the event occurs, unless you remove the delegate.

Metody rozszerzania

GetMethodInfo(Delegate)

Pobiera obiekt, który reprezentuje metodę reprezentowaną przez określony delegat.Gets an object that represents the method represented by the specified delegate.

Dotyczy