On Windows 10, I'm trying to make a window stay always on bottom; that is, it is always shown behind other windows and can't be brought on top of them. I've seen around that the easiest solution is to make the window a child of the desktop; however, I've had mixed success in doing this. The undesirable side effects of making a window child of the desktop are not a problem in this case. I've tried making my window child of SysListView32, SHELLDLL_DefView and Progman.
In the first two cases, the window does correctly stay behind, though for some reason it is partially transparent and the desktop background can be seen behind it (but not whatever files/folders may be on the desktop). In the last case the window can't be seen at all. Is there some way to take care of the transparency issue, or am I not making my window child of the right window? If it matters, I'm using Python 3.7 with Pygame (which is based on SDL) to create my window.
Instead of finding another solution, I've managed to fix the transparency issue by enabling the extended window style WS_EX_LAYERED on my window using SetWindowLong.
Making a window always stay behind