private void Form1_Load(object sender, EventArgs e)
        {
            Point[] pParam = new Point[] { new Point(12, 34), new Point(3, 5), new Point(45, 56), new Point(126, 6) };
            Point[] pIn = GetPointInPolygon(2, pParam);          

        }

        /// <summary>
        /// 获取多边形内随机坐标点
        /// </summary>
        /// <param name="count">获取左边点数量</param>
        /// <param name="point">多边形的各个点</param>
        /// <returns></returns>
        public Point[] GetPointInPolygon(int count, Point[] point)
        {
            if (point.Length < 3)
                return null; //不是多边形

            int x1 = int.MaxValue;
            int x2 = int.MinValue;
            int y1 = int.MaxValue;
            int y2 = int.MinValue;

            foreach (Point p in point)
            {
                if (p.X < x1)
                    x1 = p.X;
                if (p.X > x2)
                    x2 = p.X;
                if (p.Y < y1)
                    y1 = p.Y;
                if (p.Y > y2)
                    y2 = p.Y;
            }

            Random rnd = new Random((int)DateTime.Now.Ticks);
            Point[] pointRet = new Point[count];
            for (int i = 0; i < count; i++)
            {
                pointRet[i] = new Point(rnd.Next(x1, x2), rnd.Next(y1, y2));
            }
            return pointRet;
        }