DownloadProgressChangedEventArgs Class

    // 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");
    }

private static void UploadProgressCallback(object sender, UploadProgressChangedEventArgs e)
{
    // Displays the operation identifier, and the transfer progress.
    Console.WriteLine("{0}    uploaded {1} of {2} bytes. {3} % complete...", 
        (string)e.UserState, 
        e.BytesSent, 
        e.TotalBytesToSend,
        e.ProgressPercentage);
}
private static void DownloadProgressCallback(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);
}