c# - 覆盖 OnPaint

Question

如果我重写 OnPaint 并在控件上绘制一个正方形，当我在设计器中预览它时，如何让 e.graphics.draw... 显示出来？

Answer 1

http://msdn.microsoft.com/en-us/magazine/cc164048.aspx

http://msdn.microsoft.com/en-us/magazine/cc164145.aspx

While you could manually register with Control.OnPaint to add your design time UI, you'll find that overriding OnPaintAdornments is a better option because it is only called after the control's design-time/run-time UI is painted, letting you put the icing on the cake (see Figure 20). Simply adding DesignerAttribute to the ClockControl class completes the association: Copy Code

[ Designer(typeof(ClockControlDesigner)) ] class ClockControl : Control { ... }