How to start a thread to keep GUI refreshed?

Question

I have window with button which triggers lengthy processing. I put processing in a separate thread, but -- to my surprise -- it makes GUI frozen anyway. No control is refreshed,

Answer 1

I put processing in a separate thread, but -- to my surprise -- it makes GUI frozen anyway.

I really hate to tell you, but then you did NOT put it into a separate thread. That simlpe.

There was a poster here that had a similar issue some time ago and through a mistake in his invoking code he basically had all processing before the thread started, with the thread jsut returning the result.