WebClient.DownloadFileCompleted Evento

Definición

Espacio de nombres:

System.Net

Ensamblado:

System.Net.WebClient.dll

Source:

WebClient.cs

Se produce cuando finaliza una operación de descarga de archivo asincrónica.

public:
 event System::ComponentModel::AsyncCompletedEventHandler ^ DownloadFileCompleted;

public event System.ComponentModel.AsyncCompletedEventHandler? DownloadFileCompleted;

member this.DownloadFileCompleted : System.ComponentModel.AsyncCompletedEventHandler 

Public Custom Event DownloadFileCompleted As AsyncCompletedEventHandler 

Tipo de evento

AsyncCompletedEventHandler

Ejemplos

En el ejemplo de código siguiente se muestra cómo establecer un controlador de eventos para el DownloadFileCompleted evento.

// Sample call : DownLoadFileInBackground2 ("http://www.contoso.com/logs/January.txt");
void DownLoadFileInBackground2( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);

   // Call DownloadFileCallback2 when the download completes.
   client->DownloadFileCompleted += gcnew AsyncCompletedEventHandler( DownloadFileCallback2 );

   // Specify a progress notification handler here...

   client->DownloadFileAsync( uri, "serverdata.txt" );
}

void DownloadFileCallback2( Object^ /*sender*/, System::ComponentModel::AsyncCompletedEventArgs^ e )
{
   if ( e->Cancelled )
   {
      Console::WriteLine( "File download cancelled." );
   }

   if ( e->Error != nullptr )
   {
      Console::WriteLine( e->Error->ToString() );
   }
}

// 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);

    // Call DownloadFileCallback2 when the download completes.
    client.DownloadFileCompleted += new AsyncCompletedEventHandler(DownloadFileCallback2);

    // Specify a progress notification handler here ...

    client.DownloadFileAsync(uri, "serverdata.txt");
}

private static void DownloadFileCallback2(object sender, AsyncCompletedEventArgs e)
{
    if (e.Cancelled)
    {
        Console.WriteLine("File download cancelled.");
    }

    if (e.Error != null)
    {
        Console.WriteLine(e.Error.ToString());
    }
}

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

    Dim client As WebClient = New WebClient()

    ' Call DownloadFileCallback2 when the download completes.
    AddHandler client.DownloadFileCompleted, AddressOf DownloadFileCallback2

    ' Specify a progress notification handler here...

    Dim uri as Uri = New Uri(address)
    client.DownloadFileAsync(uri, "serverdata.txt")
End Sub

Private Shared Sub DownloadFileCallback2(sender As Object, e As AsyncCompletedEventArgs)
    If e.Cancelled = True Then
        Console.WriteLine("File download cancelled.")
    End If

    If Not e.Error Is Nothing Then
        Console.WriteLine(e.Error.ToString())
    End If
End Sub

Comentarios

Este evento se genera cada vez que se completa una operación de descarga de archivos asincrónica. Las descargas de archivos asincrónicas se inician mediante una llamada a los DownloadFileAsync métodos .

AsyncCompletedEventHandler es el delegado de este evento. La AsyncCompletedEventArgs clase proporciona al controlador de eventos datos de eventos.

Para obtener más información acerca de cómo controlar eventos, vea controlar y provocar eventos.