DownloadProgressChangedEventHandler DownloadProgressChangedEventHandler DownloadProgressChangedEventHandler DownloadProgressChangedEventHandler Delegate

Definition

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

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

Parameter

sender
Object Object Object Object

Die Quelle des Ereignisses.The source of the event.

Vererbung
DownloadProgressChangedEventHandlerDownloadProgressChangedEventHandlerDownloadProgressChangedEventHandlerDownloadProgressChangedEventHandler

Beispiele

Im folgenden Codebeispiel wird das Festlegen eines Ereignis Handlers WebClient.DownloadProgressChanged für das-Ereignis veranschaulicht.The following code example demonstrates setting an event handler for the WebClient.DownloadProgressChanged event.

// Sample call : DownLoadFileInBackground2 ("http://www.contoso.com/logs/January.txt");
void DownLoadFileInBackground2( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);
   
   // Specify that the DownloadFileCallback method gets called
   // when the download completes.
   client->DownloadFileCompleted += gcnew AsyncCompletedEventHandler( DownloadFileCallback2 );
   
   // Specify a progress notification handler.
   client->DownloadProgressChanged += gcnew DownloadProgressChangedEventHandler( DownloadProgressCallback );
   client->DownloadFileAsync( uri, "serverdata.txt" );
}


// Sample call : DownLoadFileInBackground2 ("http://www.contoso.com/logs/January.txt");
public static void DownLoadFileInBackground2 (string address)
{
    WebClient client = new WebClient ();
    Uri uri = new Uri(address);

    // Specify that the DownloadFileCallback method gets called
    // when the download completes.
    client.DownloadFileCompleted += new AsyncCompletedEventHandler (DownloadFileCallback2);
    // Specify a progress notification handler.
    client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgressCallback);
    client.DownloadFileAsync (uri, "serverdata.txt");
}

'  Sample call : DownLoadFileInBackground2 ("http:' www.contoso.com/logs/January.txt")
Public Shared Sub DownLoadFileInBackground2(ByVal address As String)

	Dim client As WebClient = New WebClient()

	'  Specify that the DownloadFileCallback method gets called
	'  when the download completes.
	AddHandler client.DownloadFileCompleted, AddressOf DownloadFileCallback2
	'  Specify a progress notification handler.
	AddHandler client.DownloadProgressChanged, AddressOf DownloadProgressCallback
                      Dim uri as Uri = New Uri(address)
	client.DownloadFileAsync(uri, "serverdata.txt")
End Sub

Hinweise

Beim Erstellen eines DownloadProgressChangedEventHandler-Delegaten bestimmen Sie die Methode für die Ereignisbehandlung.When you create a DownloadProgressChangedEventHandler 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. Weitere Informationen zu Ereignishandlerdelegaten finden Sie unter behandeln und Auswerfen von Ereignissen.For more information about event handler delegates, see Handling and Raising Events. Behandeln und Auswerfen von EreignissenHandling and Raising Events

Hinweis

Wenn der Server die Größe der heruntergeladenen Datei (z. b. bei einer passiven FTP-Verbindung) nicht sendet, ist ProgressPercentage möglicherweise immer 0 (null).If the server does not send the size of the downloaded file (such as in the case of a passive FTP connection), ProgressPercentage may always be zero.

Erweiterungsmethoden

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

Ruft ein Objekt ab, das die Methode darstellt, die vom angegebenen Delegaten dargestellt wird.Gets an object that represents the method represented by the specified delegate.

Gilt für: