Transparent fill

[Abdullah211w]

I want to draw a circle or a polygon with color fill of 50% opacity.
Can you help please?

[sweco-sedahd]

On the ShapeDrawingOptions object you are setting the drawing style you only need to set FillTransparency to make the fill be transparent. From documentation: Ranges from 0 (transparent) to 255 (opaque).
So to get 50 % you need to set it to half of 255 (128).