DownloadProgressChangedEventHandler DownloadProgressChangedEventHandler DownloadProgressChangedEventHandler DownloadProgressChangedEventHandler Delegate

Definición

Representa el método que controlará el evento DownloadProgressChanged de WebClient.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)

Parámetros

sender
Object Object Object Object

Origen del evento.The source of the event.

Herencia
DownloadProgressChangedEventHandlerDownloadProgressChangedEventHandlerDownloadProgressChangedEventHandlerDownloadProgressChangedEventHandler

Ejemplos

En el ejemplo de código siguiente se muestra cómo establecer un controlador de eventos para el WebClient.DownloadProgressChanged eventos.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

Comentarios

Cuando se crea un delegado DownloadProgressChangedEventHandler, se identifica el método que controlará el evento.When you create a DownloadProgressChangedEventHandler delegate, you identify the method that will handle the event. Para asociar el evento al controlador, se debe agregar una instancia del delegado al evento.To associate the event with your event handler, add an instance of the delegate to the event. Siempre que se produce el evento, se llama a su controlador, a menos que se quite el delegado.The event handler is called whenever the event occurs, unless you remove the delegate. Para obtener más información sobre los delegados de controlador de eventos, consulte controlar y provocar eventos.For more information about event handler delegates, see Handling and Raising Events. Controlar y provocar eventosHandling and Raising Events

Nota

Si el servidor no envía el tamaño del archivo descargado (como en el caso de una conexión FTP pasivo), ProgressPercentage siempre puede ser cero.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.

Métodos de extensión

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

Obtiene un objeto que representa el método representado por el delegado especificado.Gets an object that represents the method represented by the specified delegate.

Se aplica a