For sure, it is possible to do it with .NET.
See Displaying FTP/SFTP transfer progress on WinForms ProgressBar.

Hello,

the main problem is, that the GUI is blocked. Meanwhile I changed the code. Now I do not make the transfer with .NET but with a script file. This way it works.

Regards Denis.

Is the mouse cursor the actual issue? Or is the cursor just a way how the Windows tells you that your code is blocking the GUI thread?

Hello,

I am using WinSCP 5.21.8.0 via .NET. While the session to the (S)FTP-host is open and the file is transfered the mouse cursor appears (spinning wheel) and although the upload is running in a parallel thread this blocks other threads of the application.
Is there any parameter to avoid the mouse cursor?

Regards Denis.