Display progress of asynchronous SSH.NET SFTP upload (BeginUploadFile) on progress bar

Question

I'm using Renci SSH.NET as SFTP client in C#.
Now I'm making a progress bar with this API. I tried with async and await, but I could not find the solution for getting downloaded bytes. I tried this way:

1. Could you let me know problem with my code?

2. Is there any way to try using async, await with Renci SSH.NET? And get some downloaded or uploaded bytes from API.

IAsyncResult UploadResult = sftp.BeginUploadFile(stream, remotepath + "/" + 
Path.GetFileName(localpath));

SftpUploadAsyncResult UploadProgress = new SftpUploadAsyncResult(null, UploadResult.AsyncState);

Window_Progress wp = new Window_Progress();
Point _pt = MainWindow.current.PointToScreen(new 
Point((MainWindow.current.Width - wp.Width) / 2,
(MainWindow.current.Height - wp.Height) / 2));
wp.Left = _pt.X;
wp.Top = _pt.Y;

while (!UploadProgress.IsCompleted)
{
    UploadProgress = new SftpUploadAsyncResult(null,UploadResult.AsyncState);
    Thread.Sleep(10);
    wp.PartialProgressBar.Value = (UploadProgress.UploadedBytes / 
    FilesAndDirectory.GetSize(localpath) * 100);
}

UploadProgress.AsyncWaitHandle.WaitOne();
wp.Close();

Answer 1

First, your code has numerous flaws:

• You are using "async" method, and then you synchronously wait for it to complete.
• You even process a result in a loop, presumably from a GUI thread, without pumping a GUI message queue.
• SftpUploadAsyncResult won't get your upload progress, when you create your own instance. Pass it the "state" object won't help. You should cast UploadResult returned by BeginUploadFile to SftpUploadAsyncResult, instead of creating a new SftpUploadAsyncResult.

---

Anyway, as I do not think that SftpClient class itself has any event that would trigger on upload progress, easiest solution is to use uploadCallback parameter (4th) of BeginUploadFile, the same way it's used with synchronous upload. See Displaying progress of file upload in a ProgressBar with SSH.NET.

sftp.BeginUploadFile(
    stream, remotepath + "/" + Path.GetFileName(localpath), null, null, UpdateProgresBar);

And then it's questionable whether using "async" upload has any advantage with SftpClient. There's no "async" variant for Connect method, so you need a thread/task for that anyway, so why don't you also upload a file from that thread right away?