/// <summary>
 /// 比较两个节点的F值
 /// </summary>
 /// <param name="x">第一个节点</param>
 /// <param name="y">第二个节点</param>
 /// <returns></returns>
 private int Compare(PathNote x, PathNote y)
 {
     if (x.F > y.F)
         return 1;
     else if (x.F < y.F)
         return -1;
     return 0;
 }
        /// <summary>
        /// 开始寻找路径
        /// </summary>
        /// <returns></returns>
        public List<Point> StartFindPath()
        {
            var found = false;
            var pathNote = new PathNote() { F = 0, G = 0, H = 0, X = (int)startPoint.X, Y = (int)startPoint.Y, parentNote = null };
            List<Point> resultPoints = null;
            while (true)
            {
                for (int i = 0; i < (diagonals ? 8 : 4); i++)  //找到pathNote四方向或八方向周围节点,取F值最小的那个继续此过程
                {
                    var x = pathNote.X + direction[i, 0];
                    var y = pathNote.Y + direction[i, 1];

                    if (x < 0 || y < 0 || x > matrix.GetUpperBound(0) || y > matrix.GetUpperBound(1)) //坐标过界
                        continue;

                    var newPathNote = new PathNote();
                    newPathNote.parentNote = pathNote;
                    newPathNote.X = x;
                    newPathNote.Y = y;

                    bool isClosed = false;
                    bool isOpened = false;
                    PathNote theOpendandSameNote = null;
                    foreach (var closedNote in colsedList)
                    {
                        if (closedNote.X == newPathNote.X && closedNote.Y == newPathNote.Y)
                        {
                            isClosed = true;  //节点已经在关闭列表中
                        }
                    }

                    foreach (var openedNote in openedList)
                    {
                        if (openedNote.X == newPathNote.X && openedNote.Y == newPathNote.Y)
                        {
                            isOpened = true; //节点已经在开启列表中,稍后比较两条路径
                            theOpendandSameNote = openedNote;
                        }
                    }

                    if (matrix[newPathNote.X, newPathNote.Y] != 0 || isClosed) //不能通行或者已经在关闭列表中存在
                        continue;

                    if (Math.Abs(direction[i, 0] + direction[i, 1]) == 2)  //G值
                    {
                        newPathNote.G = newPathNote.parentNote.G + 14;
                    }
                    else
                    {
                        newPathNote.G = newPathNote.parentNote.G + 10;
                    }

                    newPathNote.H = (int)(Math.Abs(endPoint.X - newPathNote.X) + Math.Abs(endPoint.Y - newPathNote.Y)) * 10;  //H值
                    newPathNote.F = newPathNote.G + newPathNote.H;  //F值


                    if (isOpened) //比较已在开启列表中的节点G值和准备创建的节点G值
                    {
                        if (newPathNote.G >= theOpendandSameNote.G)
                        {
                            this.openedList.Remove(pathNote);
                            continue;
                        }
                        else
                        {
                            this.openedList.Remove(theOpendandSameNote);
                            this.openedList.Add(newPathNote);
                            continue;
                        }
                    }

                    this.openedList.Add(newPathNote); //创建节点(添加进开启列表)
                }
                this.colsedList.Add(pathNote); //把当前节点放进关闭列表
                this.openedList.Remove(pathNote); //从开启列表移除当前节点
                foreach (var openedNote in openedList)
                {
                    if (openedNote.X == (int)endPoint.X && openedNote.Y == (int)endPoint.Y) // 到达终点
                    {
                        resultPoints = GetPointListByParent(openedNote, null); //得到以Point构成的路径
                        found = true;
                        break;
                    }
                }

                if (found)
                {
                    break;
                }
                else
                {
                    if (openedList.Count == 0)  //找不到路径
                    {
                        break;
                    }
                    else
                    {
                        openedList.Sort(Compare);
                        pathNote = openedList[0];
                    }
                }
            }
            return resultPoints;
        }
 /// <summary>
 /// 组织传入的PathNote的所有父节点为List
 /// </summary>
 /// <param name="pathNote">PathNote</param>
 /// <param name="pathPoints">列表</param>
 /// <returns>路径</returns>
 private List<Point> GetPointListByParent(PathNote pathNote, List<Point> pathPoints)
 {
     if (pathPoints == null)
         pathPoints = new List<Point>();
     if (pathNote.parentNote != null)
     {
         pathPoints.Add(new Point(pathNote.parentNote.X, pathNote.parentNote.Y));
         GetPointListByParent(pathNote.parentNote, pathPoints);
     }
     return pathPoints;
 }