UploadFileCompletedEventHandler Делегат

Определение

Пространство имен:

System.Net

Сборка:

System.Net.WebClient.dll

Представляет метод, обрабатывающий событие UploadFileCompleted объекта WebClient.

public delegate void UploadFileCompletedEventHandler(System::Object ^ sender, UploadFileCompletedEventArgs ^ e);

public delegate void UploadFileCompletedEventHandler(object sender, UploadFileCompletedEventArgs e);

type UploadFileCompletedEventHandler = delegate of obj * UploadFileCompletedEventArgs -> unit

Public Delegate Sub UploadFileCompletedEventHandler(sender As Object, e As UploadFileCompletedEventArgs)

Параметры

sender

Object

Источник события.

e

UploadFileCompletedEventArgs

Объект UploadFileCompletedEventArgs, содержащий данные события.

Примеры

В следующем примере кода демонстрируется асинхронная отправка файла.

// Sample call: UploadFileInBackground("http://www.contoso.com/fileUpload.aspx", "data.txt")
void UploadFileInBackground( String^ address, String^ fileName )
{
   System::Threading::AutoResetEvent^ waiter = gcnew System::Threading::AutoResetEvent( false );
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);
   String^ method = "POST";

   // Specify that that UploadFileCallback method gets called
   // when the file upload completes.
   client->UploadFileCompleted += gcnew UploadFileCompletedEventHandler( UploadFileCallback );
   client->UploadFileAsync( uri, method, fileName, waiter );

   // Block the main application thread. Real applications
   // can perform other tasks while waiting for the upload to complete.
   waiter->WaitOne();
   Console::WriteLine( "File upload is complete." );
}

// Sample call: UploadFileInBackground("http://www.contoso.com/fileUpload.aspx", "data.txt")
public static void UploadFileInBackground(string address, string fileName)
{
    System.Threading.AutoResetEvent waiter = new System.Threading.AutoResetEvent(false);
    WebClient client = new WebClient();
    Uri uri = new Uri(address);
    string method = "POST";

    // Specify that that UploadFileCallback method gets called
    // when the file upload completes.
    client.UploadFileCompleted += new UploadFileCompletedEventHandler(UploadFileCallback);
    client.UploadFileAsync(uri, method, fileName, waiter);

    // Block the main application thread. Real applications
    // can perform other tasks while waiting for the upload to complete.
    waiter.WaitOne();
    Console.WriteLine("File upload is complete.");
}

'  Sample call: UploadFileInBackground("http:' www.contoso.com/fileUpload.aspx", "data.txt")
Public Shared Sub UploadFileInBackground(ByVal address As String, ByVal fileName As String)

    Dim waiter As System.Threading.AutoResetEvent = New System.Threading.AutoResetEvent(False)
    Dim client As WebClient = New WebClient()
    Dim method As String = "POST"
                 Dim uri as Uri =  New Uri(address)

    '  Specify that that UploadFileCallback method gets called
    '  when the file upload completes.
    AddHandler client.UploadFileCompleted, AddressOf UploadFileCallback
    client.UploadFileAsync(uri, method, fileName, waiter)

    '  Block the main application thread. Real applications
    '  can perform other tasks while waiting for the upload to complete.
    waiter.WaitOne()
    Console.WriteLine("File upload is complete.")
End Sub

Следующий метод вызывается по завершении отправки.

void UploadFileCallback( Object^ /*sender*/, UploadFileCompletedEventArgs^ e )
{
   System::Threading::AutoResetEvent^ waiter = dynamic_cast<System::Threading::AutoResetEvent^>(e->UserState);
   ;
   try
   {
      String^ reply = System::Text::Encoding::UTF8->GetString( e->Result );
      Console::WriteLine( reply );
   }
   finally
   {

      // If this thread throws an exception, make sure that
      // you let the main application thread resume.
      waiter->Set();
   }

}

private static void UploadFileCallback(Object sender, UploadFileCompletedEventArgs e)
{
    System.Threading.AutoResetEvent waiter = (System.Threading.AutoResetEvent)e.UserState; ;
    try
    {
        string reply = System.Text.Encoding.UTF8.GetString(e.Result);

        Console.WriteLine(reply);
    }
    finally
    {
        // If this thread throws an exception, make sure that
        // you let the main application thread resume.
        waiter.Set();
    }
}

Private Shared Sub UploadFileCallback(ByVal sender As Object, ByVal e As System.Net.UploadFileCompletedEventArgs)

    Dim waiter As System.Threading.AutoResetEvent = CType(e.UserState, System.Threading.AutoResetEvent)
    Try

        Dim reply As String = System.Text.Encoding.UTF8.GetString(e.Result)
        Console.WriteLine(reply)
    Finally
        '  If this thread throws an exception, make sure that
        '  you let the main application thread resume.
        waiter.Set()
    End Try
End Sub

Комментарии

При создании делегата UploadFileCompletedEventHandler необходимо указать метод, обрабатывающий событие. Чтобы связать событие с обработчиком событий, нужно добавить в событие экземпляр делегата. Обработчик событий вызывается всякий раз, когда происходит событие, если делегат не удален. Дополнительные сведения о делегатах обработчиков событий см. в разделе Обработка и вызов событий.

Методы расширения

GetMethodInfo(Delegate)

Получает объект, представляющий метод, представленный указанным делегатом.