图形要素:4个点、颜色、作图对象、数据
Graphics g;//创建Graphics对象 private void button1_Click(object sender, EventArgs e) { Bitmap bt = new Bitmap(panel1.Width, panel1.Height);//实例化一个Bitmap对象 int flag = (panel1.Width-4 )/ 6;//X轴的增值 g = Graphics.FromImage(bt);//实例化Graphics对象 Pen p = new Pen(Color.Black, 1);//设置Pen对象 g.DrawLine(p, new Point(0, 0), new Point(0, panel1.Height-20));//绘制Y轴 g.DrawLine(p, new Point(0, panel1.Height - 20), new Point(panel1.Width - 4, panel1.Height - 20));//绘制X轴 //声明一个用于绘制颜色的数组 Color[] cl = new Color[] { Color.Red, Color.Blue, Color.YellowGreen, Color.Yellow, Color.RoyalBlue, Color.Violet, Color .Tomato}; int[] points = { 20,70,80,60,40,100,10};//声明一个计算走势峰值的数组 Point pt1 = new Point(0, panel1.Height - 20 - points[0]);//记录绘制四边形的第一个点 Point pt2 = new Point(0, panel1.Height - 20);//记录绘制四边形的第二个点 for (int i = 0; i <= 6; i++)//通过for循环绘制月份和面形图 { PointF p1 = new PointF(flag * i, panel1.Height - 20);//计算每个月份数字的坐标 //绘制显示月份的数字 g.DrawString(i.ToString(), new Font("宋体", 9), new SolidBrush(Color.Black), new PointF(p1.X - 2, p1.Y)); //记录绘制四边形的第三个点 Point pt3 = new Point(flag * i, panel1.Height - 20); //记录绘制四边形的第四个点 Point pt4 = new Point(flag * i, panel1.Height - 20 - points[i]); Point[] pt={pt1,pt2,pt3,pt4};//声明一个Point数组 g.FillPolygon(new SolidBrush(cl[i]), pt);//填充四边形的颜色 //当继续绘制下一个四边形时,前一个四边形的最后两个点作为下一个四边形的起始点 pt1 = pt4; pt2 = pt3; } panel1.BackgroundImage = bt;//显示绘制的面形图 }