private void MainForm_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
//点的大小, 值一样则是画点
float[] BlueValues = {5, 15 20,25s};
//颜色及画笔大小设置
Pen BluekPen = new Pen(Color.Blue, 1);
//指定设定值
BluekPen.DashPattern = dashValues;
//画一条竖线
e.Graphics.DrawLine(BluekPen, new Point(20, 50), new Point(20, 150));
}