採用下面兩個方法可以簡單判斷矩形框、多邊形是否包含某個點。

　　　　　/// <summary>
        /// 判斷點是否在矩形框內
        /// </summary>
        /// <param name="pt"></param>
        /// <param name="rect"></param>
        /// <returns></returns>
        public static bool PtInRect(Point pt, RectangleF rect)
        {
            GraphicsPath path 
 
= new GraphicsPath();
            Region region = new Region();
            path.Reset();
            //構建多邊形
            path.AddRectangle(rect);
            region.MakeEmpty();
            region.Union(path);
            //判斷點是否在多邊形裡
            bool rlt = region.IsVisible(pt);
            region.Dispose();
            path.Dispose();
            
 
return rlt;
        }
        /// <summary>
        /// 判斷點是否在多邊形內
        /// </summary>
        /// <param name="pt"></param>
        /// <param name="pts"></param>
        /// <returns></returns>
        public static bool PtInPolygon(Point pt, Point[] pts)
        {
            GraphicsPath path 
 
= new GraphicsPath();
            Region region = new Region();
            path.Reset();
            //構建多邊形
            path.AddPolygon(pts);
            region.MakeEmpty();
            region.Union(path);
            //判斷點是否在多邊形裡
            bool rlt = region.IsVisible(pt);
            region.Dispose();
            path.Dispose();
            return rlt;
        }