Creating FTP File Downloader Application With Background Worker

2. Function to show the progress is given below.
   
   1. void worker_ProgressChanged(object sender, ProgressChangedEventArgs e) {}

3. Function after completing the task is given below.
   
   1. private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) {}

Step 5

Let’s start filing these Background worker functions, as shown below.

1. DoWork
   
   1. private void worker_DoWork(object sender, DoWorkEventArgs e) {
   2. try {
   3. FtpWebRequest request = (FtpWebRequest) FtpWebRequest.Create(new Uri(txtUrl.Text));
   4. request.Proxy = null;
   5. request.Method = WebRequestMethods.Ftp.GetFileSize;
   6. FtpWebResponse response = (FtpWebResponse) request.GetResponse();
   7. long size = response.ContentLength;
   8. response.Close();
   9. filesize = ConvertBytesToMegabytes(size);
   10. FtpWebRequest requestFileDownload = (FtpWebRequest) WebRequest.Create(txtUrl.Text);
   11. requestFileDownload.Method = WebRequestMethods.Ftp.GetFileSize;
   12. requestFileDownload.Method = WebRequestMethods.Ftp.DownloadFile;
   13. FtpWebResponse responseFileDownload = (FtpWebResponse) requestFileDownload.GetResponse();
   14. Stream responseStream = responseFileDownload.GetResponseStream();
   15. FileStream writeStream = new FileStream(Environment.SpecialFolder.Desktop + "File.zip", FileMode.Create);
   16. int Length = 1024;
   17. Byte[] buffer = new Byte[Length];
   18. int bytesRead = responseStream.Read(buffer, 0, Length);
   19. while (bytesRead > 0) {
   20. writeStream.Write(buffer, 0, bytesRead);
   21. bytesRead = responseStream.Read(buffer, 0, Length);
   22. filesizedownloaded = ConvertBytesToMegabytes(writeStream.Length);
   23. worker.ReportProgress(Convert.ToInt32((Convert.ToInt32(filesizedownloaded) / filesize) * 100));
   24. }
   25. responseStream.Flush();
   26. responseStream.Dispose();
   27. responseStream.Close();
   28. writeStream.Flush();
   29. writeStream.Dispose();
   30. writeStream.Close();
   31. requestFileDownload = null;
   32. responseFileDownload = null;
   33. } catch {
   34. MessageBox.Show("Your internet connection appears to be down or URL not found. Please check it and try again", "Communications Error", MessageBoxButton.OK, MessageBoxImage.Information);
   35. }
   36. }

2. worker_ProgressChanged
   
   1. void worker_ProgressChanged(object sender, ProgressChangedEventArgs e) {
   2. progressBar1.Value = e.ProgressPercentage;
   3. lblStatus.Content = "Downloading...";
   4. lblProgress.Content = "Download " + filesizedownloaded.ToString("F2") + " / " + filesize.ToString("F2") + " ( " + progressBar1.Value.ToString() + " ) % Complete.";
   5. }

3. worker_RunWorkerCompleted
   
   1. private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) {
   2. lblStatus.Content = "Download finished";
   3. try {
   4. worker.CancelAsync();
   5. worker = null;
   6. } catch {}
   7. txtUrl.Text = "";
   8. lblStatus.Content = "Copy and Paste the URL to download";
   9. txtUrl.Focus();
   10. txtUrl.Visibility = Visibility.Visible;
   11. btnDownload.Visibility = Visibility.Visible;
   12. lblProgress.Visibility = Visibility.Hidden;
   13. }

Step 6

The final step is to do the download and cancel button code, as shown below.

Now, we can run and check how it will work, which is shown below.

1. For testing, we can use ftp://speedtest.tele2.net/ link, open this link and right click on any file, which you wanted to test and select copy link location, shown below.
   
   
   

2. Paste this link to our app File Downloader Textbox, followed by clicking download now and you can see the progress without interruption or hanging, as shown below. In Destination file, I have hardcoded as E:\Test\File.zip