Quote Originally Posted by ChrisW67 View Post
You are constructing your MySplitter instance at line 5 of your first listing. At this point in time it has no widgets to split but you are assuming it does. Until you have added widgets to the splitter and the widget containing the splitter is shown there are no sizes.
Thank you, ChrisW67! It works! I should call sizes() until the parent widget is shown.

Now, I think I could go on with my work.



Tang Tao