Changing contents of EditBox while processing an Event handler in VC++ mfc

Question

When I press a button in VC++, the program starts reading data from USB which takes several minutes to be completed. During this operation I want to show the status of the progress in an edit box in the same Dialog using m_editCtrl.SetWindowTextW(output1); But during the transfer the contents of the Edit box are not changed. How can we change it?

Thanks

Since your I/O takes some time, you need to execute it on a separate thread. — rrirower, Jun 13 '17 at 18:31
Do not perform long-running tasks on your UI thread. You can either offload the work to a worker thread, or use asynchronous I/O. — IInspectable, Jun 13 '17 at 18:36

score 0 · Answer 1 · answered Jun 16 '17 at 20:26

If the main thread is busy like in a loop, it will not update GUI. You should create a thread which does the heavy lifting and the thread, in turn, should post update messages to GUI.

Here is an example to get started and will do the job but it can be improved. In this example, the thread is calling the GUI API directly but it will be even better if you post a message to parent window using HWND and it will update itself.

Changing contents of EditBox while processing an Event handler in VC++ mfc

1 Answers1