I have a very simple WPF window - the only thing in it is a right-aligned button. When I resize the window by dragging the left boundary, the button jumps around - a lot. Try it yourself, drag the left boundary back and forth.
Additionally, a black background becomes exposed temporarily during resizes.
In this question, I asked a similar question about Windows Forms. The only answer I got suggested that this is fixed in WPF, however, amazingly, not only is it not fixed, but WPF also adds a second visual bug - the temporary black background.
Here's what the control lag looks like; this occurs when I resize the window by its top border (recorded with a camera because screen-cap made it less obvious by making everything slow):
Example of the black border: this was captured while resizing the window; it's only like this for a split second but it's very noticeable:
Am I doing something wrong? How can I have my controls stay visually in one place during resizes? How can I avoid the black border?
Note: the button ends up in the correct place eventually - it only jumps around briefly during the resize.