UploadFileCompletedEventHandler Delegat

Definition

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)

Parameter

Beispiele

Das folgende Codebeispiel veranschaulicht das asynchrone Hochladen einer Datei.

// 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

Die folgende Methode wird aufgerufen, wenn der Upload abgeschlossen ist.

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

Hinweise

Wenn Sie einen UploadFileCompletedEventHandler Delegaten erstellen, identifizieren Sie die Methode, die das Ereignis behandelt. Um das Ereignis dem Ereignishandler zuzuordnen, fügen Sie dem Ereignis eine Instanz des Delegaten hinzu. Der Ereignishandler wird immer dann aufgerufen, wenn das Ereignis auftritt, es sei denn, Sie entfernen den Delegaten. Weitere Informationen zu Ereignishandlerdelegatn finden Sie unter Behandeln und Auslösen von Ereignissen.