一个点在一条直线上往返做运动的代码。

需要事先，在窗体上加入一个TIMER和一个BUTTON。

---

 

private void button1_Click(object sender, EventArgs e) { timer1.Enabled = true; } private Point pt1 = new Point(10, 10); //起点坐标 private Point pt2 = new Point(300, 300); //终点坐标 private int n = 0; //运动点离起点的距离 private bool bDirect = true; //true为从起点向终点运行，false从终点向起点运行 Point pt = new Point(0, 0); //当前点 private void timer1_Tick(object sender, EventArgs e) { //直角三角形，求斜边的长度公式 int m = (int)Math.Pow(Math.Pow((pt2.X - pt1.X), 2) + Math.Pow((pt2.Y - pt1.Y), 2), 0.5); //总距离 //判断往返 if (n >= m) bDirect = false; if (n == 0) bDirect = true; //根据往返，设置加减量 if (bDirect) n+=3; else n-=3; Pen p1 = new Pen(Color.Yellow); Pen p2 = new Pen(Color.Red); Graphics g = this.CreateGraphics(); if (pt.X != 0 && pt.Y != 0) //清除上次的运动点 { g.DrawEllipse(new Pen(this.BackColor), pt.X - 2, pt.Y - 2, 1, 1); //清除上次的运动点 } g.DrawLine(p1, pt1, pt2);//画起点到终点的线 pt.X = ((pt2.X - pt1.X) * n) / m + pt1.X; pt.Y = ((pt2.Y - pt1.Y)) * n / m + pt1.Y; g.DrawEllipse(p2, pt.X - 2, pt.Y - 2, 1, 1); //画运动的点 g.Dispose(); }