MessageBox on worker thread

Question

My application has a worker thread doing some files synchronisation.

Under certain condition during the sync process, my worker thread needs to make a decision to continue or not. Hence, I think I would ask for user feedback by showing a dialog box/message box.. (Yes/No). Which would cause the worker to either continue or stop.

Now the question is:
Is it safe to show message box on non UI thread?
Would it possibly cause any potential issues?

Answer 1

Is it safe to show message box on non UI thread ?

Yes it is safe. MessageBox.Show() is a static thread-safe method.

would it possibly cause any potential issues ?

Not in this scenario I think. But you do block a Thread, not something you should do when you can prevent it.

Answer 2

MessageBox is not tied to the UI. It is a simple Win32 API call. You can use it on any thread.