DownloadProgressChangedEventHandler Délégué

Définition

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)

Paramètres

Exemples

L’exemple de code suivant illustre la définition d’un gestionnaire d’événements pour l’événement DownloadProgressChanged .

// Sample call : DownLoadFileInBackground4 ("http://www.contoso.com/logs/January.txt");
void DownLoadFileInBackground4( String^ address )
{
   WebClient^ client = gcnew WebClient;
   Uri ^uri = gcnew Uri(address);

   // Specify a DownloadFileCompleted handler here...

   // Specify a progress notification handler.
   client->DownloadProgressChanged += gcnew DownloadProgressChangedEventHandler( DownloadProgressCallback4 );
   
   client->DownloadFileAsync( uri, "serverdata.txt" );
}

static void DownloadProgressCallback4(Object^ sender, DownloadProgressChangedEventArgs^ e)
{
   // Displays the operation identifier, and the transfer progress.
   Console::WriteLine("{0}    downloaded {1} of {2} bytes. {3} % complete...",
      (String ^)e->UserState,
      e->BytesReceived,
      e->TotalBytesToReceive,
      e->ProgressPercentage);
}

// Sample call : DownLoadFileInBackground4 ("http://www.contoso.com/logs/January.txt");
public static void DownLoadFileInBackground4(string address)
{
    WebClient client = new WebClient();
    Uri uri = new Uri(address);

    // Specify a DownloadFileCompleted handler here...

    // Specify a progress notification handler.
    client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgressCallback4);

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

private static void DownloadProgressCallback4(object sender, DownloadProgressChangedEventArgs e)
{
    // Displays the operation identifier, and the transfer progress.
    Console.WriteLine("{0}    downloaded {1} of {2} bytes. {3} % complete...",
        (string)e.UserState,
        e.BytesReceived,
        e.TotalBytesToReceive,
        e.ProgressPercentage);
}

' Sample call : DownLoadFileInBackground4 ("http://www.contoso.com/logs/January.txt");
Public Shared Sub DownLoadFileInBackground4(ByVal address As String)

    Dim client As WebClient = New WebClient()

    ' Specify a DownloadFileCompleted handler here...

    '  Specify a progress notification handler.
    AddHandler client.DownloadProgressChanged, AddressOf DownloadProgressCallback4

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

End Sub

Private Shared Sub DownloadProgressCallback4(ByVal sender As Object, ByVal e As DownloadProgressChangedEventArgs)
    ' Displays the operation identifier, and the transfer progress.
    Console.WriteLine("{0}    downloaded {1} of {2} bytes. {3} % complete...", _
    CStr(e.UserState), e.BytesReceived, e.TotalBytesToReceive, e.ProgressPercentage)
End Sub

Remarques

Lorsque vous créez un délégué DownloadProgressChangedEventHandler, vous identifiez la méthode qui gérera l'événement. Pour associer l'événement au gestionnaire d'événements, ajoutez une instance du délégué à l'événement. Le gestionnaire d'événements est appelé chaque fois qu'un événement se produit, sauf si vous supprimez le délégué. Pour plus d’informations sur les délégués de gestionnaires d’événements, consultez Gestion et déclenchement d’événements.

Méthodes d’extension

S’applique à