C#

    Uri srcURI = new Uri(SourceURL);
    if (srcURI.Scheme != Uri.UriSchemeFtp)
        throw new Exception("URL has invalid format");
    FtpWebRequest webReq = (FtpWebRequest)(WebRequest.Create(srcURI));
    webReq.Method = WebRequestMethods.Ftp.DownloadFile;
    webReq.Timeout = 5000;
    webReq.ReadWriteTimeout = 10000;
    webReq.UseBinary = true;
    webReq.UsePassive = true;
    webReq.KeepAlive = false;
    webReq.Proxy = proxy;
    webReq.CachePolicy = new RequestCachePolicy(RequestCacheLevel.NoCacheNoStore);

    try
    {
        FtpWebResponse webResp=(FtpWebResponse)(WebReq.GetResponse());
        if (webResp.ContentLength == -1)
            throw new Exception(string.Format("Can't download file: {0}",
                WebReq.RequestUri.Segments[WebReq.RequestUri.Segments.Length - 1]));

        string fname = WebReq.RequestUri.Segments[WebReq.RequestUri.Segments.Length - 1];
        OnUpdateDownloadStatus(string.Format("Downloading file {0}", fname), -2);

        string path = string.Format(@"{0}\{1}", DestFolder,
            fname);
        Stream fs = File.Open(path, FileMode.Create);
        int cnt = 0;
        using (BinaryWriter bw = new BinaryWriter(fs))
        {
            byte[] buf = new byte[ChunkSize];
            using (Stream s = webResp.GetResponseStream())
            {
                do
                {
                    if (AbortDownload)
                        throw new Exception("Downloading was canceled");

                    cnt = s.Read(buf, 0, ChunkSize);
                    bw.Write(buf, 0, cnt);
                    int percent = (int)(bw.BaseStream.Length * 100 / webResp.ContentLength);
                    OnUpdateDownloadStatus(
                        string.Format("Downloading file {0} : {1} %", fname, percent), percent);
                }
                while (cnt > 0);
            }
        }
    }
    catch (Exception exc)
    {
        StatusMessage=exc.Message;
    }
    finally
    {
        if (webResp != null)
            webResp.Close();
        OnDownloadComplit(StatusMessage);
    }
}