Any idea why a picturebox in a MDI parent would show on top of a MDI child? (even when MDI child = topmost)
When calling picturebox.SendToBack the picturebox disappears in the MDI parent.
What I did was, created a borderless form with the picturebox on it, and threw it on the MDI parent as a MDI child, seems to do the job!
来源：https://stackoverflow.com/questions/7814968/vb-net-picturebox-on-top-of-mdi-child