Android canvas clipPath：使剪切区域透明

Question

I've created a custom view in Android which requires a curved edge which I've implemented using canvas.clipPath . This works with the exception that the clipped region shows a grey background colour instead of being transparent.

In this image the right hand black colour is the content, which should show through the clipped region. The green is the view, and the grey to the immediate right of the view is the region which should be transparent, eg in this example the grey should be black.

Here is my (Xamarin) code:

public override void Draw(Canvas canvas)
{
    var path = new Path();
    path.AddRect(0,0,this.Width-100,this.Height, Path.Direction.Cw);
    path.AddArc(new RectF(this.Width-200, -100, this.Width, this.Height+100), 270, 180);
    canvas.ClipPath(path);
    base.Draw(canvas);
}

Is is possible to make the clipped regions of a canvas transparent?

(By the way I'm aware I shouldn't be instantiating objects in Draw , this is just for brevity)

Answer 1

I was barking up the wrong tree, so would have been hard for anyone to answer without additional information!

The leftmost grey was actually the correct background colour. The right most grey was a dimmed version of the true grey because the curved panel is actually a menu hidden in a drawer layout, so the default Android dimming was coming into play.