绘制具有多个孔的多边形？

Question

我想绘制一个多边形的多个孔。我试过下面的代码，它不能正常工作。请指教。

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); 

第一部分是外部多边形。第二和第三部分是多边形内的两个孔。

Answer 1

改为使用GraphicsPath。你可以用Graphics.FillPath来绘制，像这样：

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); 
    }