C＃如何使图形绘制的重叠区域更暗

Question

I am working on a small project that draws many filled circles on a form with the Graphics class and SolidBrushes. Is there a way to make areas darker when graphics are overlapping? I would like to have it so as more circles overlap, the overlapped areas get gradually darker in whatever color the circles are drawn in.

I have looked over the Graphics class documentation but I can't seem to find anything talking about this in it...but I might have missed something.

Any help is greatly appreciated! Thank you!

Answer 1

You have a couple of options, when a shape is transparent you will get the behavior you need.

a) Set opacity less than 1

<Ellipse Height="10" Width="10" Fill="#101010" Opacity="0.5"></Ellipse>

b) Use alpha colors to fill your shapes.

<Ellipse Height="10" Width="10" Fill="#50101010"></Ellipse>

Notice the Fill property of b) includes "alpha", that indicates opacity,

#50(alpha)10(Red)10(green)10(blue)