五角星

绘制五角星

全局变量

• 静态存储变量

  Graphics g;
  Pen pen = new Pen(Color.Red);

相关事件

• 窗体加载

  private void Form1_Load(object sender, EventArgs e)
  {
      g = pictureBox1.CreateGraphics();
  }

• pictureBox点击事件

  private void pictureBox1_MouseDown_1(object sender, MouseEventArgs e)
  {
      double delta = 36*Math.PI/180;
      double r1 = 20;
      double r2 = 0.381966 * r1;
      Point[] endPoints = new Point[10];
      for (int i = 0; i < 10; ++i)
      {
          if (1 == i % 2)
          {
              endPoints[i].X = Convert.ToInt16(r1 * Math.Cos(i * delta) + e.X);
              endPoints[i].Y = Convert.ToInt16(r1 * Math.Sin(i * delta) + e.Y);
          }
          else
          {
              endPoints[i].X = Convert.ToInt16(r2 * Math.Cos(i * delta) + e.X);
              endPoints[i].Y = Convert.ToInt16(r2 * Math.Sin(i * delta) + e.Y);
          }
          
      }
      g.DrawPolygon(pen, endPoints);
  }