Drawing polygon with more than one hole?

c#, c++, gdi, gdi+

Solution

Use a `GraphicsPath` instead. You can draw it with `Graphics.FillPath`, like this:

using System.Drawing.Drawing2D;
...
    using (var gp = new GraphicsPath()) {
        PointF[] outer = new PointF[] { new PointF(0, 0), new PointF(100, 0), 
            new PointF(100, 100), new PointF(0, 100), new PointF(10, 80),new PointF(0, 0) };
        gp.AddPolygon(outer);  
        PointF[] inner1 = new PointF[] { new PointF(10, 10), new PointF(10, 20), 
            new PointF(20, 20), new PointF(20, 10), new PointF(10, 10) };
        gp.AddPolygon(inner1);
        PointF[] inner2 = new PointF[] { new PointF(40, 10), new PointF(40, 20), 
            new PointF(60, 20), new PointF(60, 10), new PointF(40, 10) };
        gp.AddPolygon(inner2);
        e.Graphics.FillPath(Brushes.Black, gp);
    }

Problem

I'm trying to draw a polygon with more than one holes. I tried the following code and it does not work correctly. Please advise. ``` PointF[] mypoly = new PointF[6 + 5 + 5]; mypoly[0] = new PointF(0, 0); mypoly[1] = new PointF(100, 0); mypoly[2] = new PointF(100, 100); mypoly[3] = new PointF(0, 100); mypoly[4] = new PointF(10, 80); mypoly[5] = new PointF(0, 0); mypoly[6] = new PointF(10, 10); mypoly[7] = new PointF(10, 20); mypoly[8] = new PointF(20, 20); mypoly[9] = new PointF(20, 10); mypoly[10] = new PointF(10, 10); mypoly[11] = new PointF(40, 10); mypoly[12] = new PointF(40, 20); mypoly[13] = new PointF(60, 20); mypoly[14] = new PointF(60, 10); mypoly[15] = new PointF(40, 10); g.FillPolygon(new SolidBrush(Color.Red), mypoly, FillMode.Winding); ``` The first part is the outer polygon. The second and the third parts are the two holes inside the polygon.

Original source