/// <summary>
/// 根据中心点、半径、角度,求半径另一端的坐标。注意用的是笛卡尔坐标系
/// </summary>
/// <param name="center">中心点</param>
/// <param name="angle">半径角度</param>
/// <param name="radius">半径长度</param>
/// <returns>半径另一端的坐标</returns>
public static Point CenterRadiusPoint(Point center, double angle, double radius)
{
Point p = new Point();
double angleHude = angle * Math.PI / 180;/*角度变成弧度*/
p.X = (int)(radius * Math.Cos(angleHude)) + center .X;
p.Y = (int)(radius * Math.Sin(angleHude)) + center .Y;
return p;
}