一、从GMap的鼠标移动、拖动开始说起

一个项目用到了地图控件
我们知道Winform的窗体一般都有MouseClick、MouseUp、MouseDown还有MouseMove等的事件
因为我这个是一个地图控件，控件里有自己加好的标注图层
所以又多了OnMarkerClick 、OnMarkerEnter、OnMarkerLeave事件

我做的功能是：有两个RadioButton（即只能选一种情况：编辑模式和测距模式）
编辑模式：可以移动(MouseDrag)还有添加Marker
测距模式: 此时关闭编辑状态，因为怕点击就会误触Marker，点击前后两点，计算距离(Click)

我自己的想法是：在两个RadioButton的CheckChanged的时候，定义了两个全局bool变量
IsEditable和IsCalDistance，赋相应的值就行了;
然后编辑模式需要考虑点击“MarkerClick”当前的点属于哪个图层，“拖动”到新位置：MarkerLeave，新位置“MarkerEnter”新点；
测距模式就需要考虑“两次”点击：—-这块可能有问题—待解决
第一次点击，此时StartPoint和EndPoint都为null，给StartPoint赋值
第二次点击时，给EndPoint赋值，顺便计算
第三次点击时，EndPoint作为了StartPoint，EndPoint为null
继续重复二
可能这一部分程序思路有问题

1.OnMarkerClick事件—-是指在鼠标点击地图控件引发此事件
2.OnMarkerEnter事件—-
3.OnMarkerLeave事件—-

控件的MouseDown首先记录位置，事件，还有记录鼠标已经按下
timemousedown是指落下时间，就在

  1.         private void gmap_MouseDown(object sender, MouseEventArgs e)
  2.         {
  3.             timemousedown = DateTime.Now;
  4.             mousepress_x = e.X;
  5.             mousepress_y = e.Y;
  6.             isMouseDown = true;
  7.         }
  8.         int isSetPoint = 0;//设置起止点，1为起点，2为终点
  9.         PointLatLng startPoint = PointLatLng.Empty;
  10.         PointLatLng endPoint = PointLatLng.Empty;
  11.         PointLatLng clickPos = PointLatLng.Empty;
  12.         private void gmap_MouseClick(object sender, MouseEventArgs e)
  13.         {
  14.             clickPos = this.gmap.FromLocalToLatLng(e.X, e.Y);
  15.             SetTxtLatLng(clickPos);
  16.             if (clickMarker != null && clickMarker.Position != clickPos)
  17.             {
  18.                 ((GMarkerGoogleExt)clickMarker).AddRect = false;
  19.             }
  20.             if (isMarkerEditable)//编辑模式下可以移动和添加标注
  21.             {
  22.                 if (timemousedown.AddMilliseconds(timemillSecond) > DateTime.Now)
  23.                 {
  24.                     isMouseDrag = false;
  25.                 }
  26.                 else
  27.                 {
  28.                     isMouseDrag = true;
  29.                 }
  30.                 int x_dis = (mousepress_x > e.X) ? mousepress_x - e.X : e.X - mousepress_x;
  31.                 int y_dis = (mousepress_y > e.Y) ? mousepress_y - e.Y : e.Y - mousepress_y;
  32.                 if (mousedistance < System.Math.Sqrt(x_dis * x_dis + y_dis * x_dis))
  33.                 {
  34.                     isMouseDrag = true;//拖拽
  35.                 }
  36.                 if (!isMouseDrag)
  37.                 {
  38.                     PointLatLng p = gmap.FromLocalToLatLng(e.X, e.Y);
  39.                     GMapMarker marker = new GMarkerGoogle(p, GMarkerGoogleType.blue_dot);
  40.                     marker.IsVisible = true;
  41.                     marker.ToolTipText = string.Format("经度{0},纬度:{1}", marker.Position.Lng, marker.Position.Lat);
  42.                     mouseOverlay.Markers.Add(marker);
  43.                 }
  44.             }
  45.             if (isCalDistanceMode)//测距模式下不能移动和添加标注
  46.             {
  47.                 if (timemousedown.AddMilliseconds(timemillSecond) > DateTime.Now)
  48.                 {
  49.                     //isMouseDrag = false;
  50.                     isMouseDrag = true;
  51.                 }
  52.                 else
  53.                 {
  54.                     //isMouseDrag = true;
  55.                     isMouseDrag = false;
  56.                 }
  57.                 int x_dis = (mousepress_x > e.X) ? mousepress_x - e.X : e.X - mousepress_x;
  58.                 int y_dis = (mousepress_y > e.Y) ? mousepress_y - e.Y : e.Y - mousepress_y;
  59.                 if (mousedistance < System.Math.Sqrt(x_dis * x_dis + y_dis * x_dis))
  60.                 {
  61.                     isMouseDrag = true;//拖拽
  62.                 }
  63.                 if (!isMouseDrag)
  64.                 {
  65.                     PointLatLng point = this.gmap.FromLocalToLatLng(e.X, e.Y);
  66.                     if (isSetPoint == 0)
  67.                     {
  68.                         isSetPoint = 1;//设置起始点
  69.                     }
  70.                     else if (isSetPoint == 1)
  71.                     {
  72.                         isSetPoint = 2;
  73.                     }
  74.                     else if (isSetPoint == 2)
  75.                     {
  76.                         isSetPoint = 1;
  77.                     }
  78.                     switch (isSetPoint)
  79.                     {
  80.                         case 1:
  81.                             //起点
  82.                             if (clickMarker != null)
  83.                             { startPoint = clickMarker.Position; }
  84.                             else
  85.                             { startPoint = point; }
  86.                             clickMarker = null;
  87.                             txtStatic.Caption = "当前为起始点";
  88.                             //纬度，经度
  89.                             txt_Coordinate.EditValue = string.Format("{0},{1}", startPoint.Lat.ToString(), startPoint.Lng.ToString());
  90.                             break;
  91.                         case 2:
  92.                             //终点
  93.                             if (clickMarker != null)
  94.                             {
  95.                                 endPoint = clickMarker.Position;
  96.                             }
  97.                             else
  98.                             {
  99.                                 endPoint = point;
  100.                             }
  101.                             clickMarker = null;
  102.                             txtStatic.Caption = "当前为结束点";
  103.                             txtLatLng.EditValue = string.Format("{0},{1}", endPoint.Lat.ToString(), endPoint.Lng.ToString());
  104.                             txtLatLng.AutoFillWidthInMenu = DevExpress.Utils.DefaultBoolean.True;
  105.                             break;
  106.                         default:
  107.                             break;
  108.                     }
  109.                     if (startPoint != PointLatLng.Empty && endPoint != PointLatLng.Empty)
  110.                     {
  111.                         txtLength.Caption = string.Format("测距距离:{0}", GetDistance(startPoint, endPoint).ToString());
  112.                     }
  113.                     if (clickRoute != null)
  114.                     {
  115.                         txtStatic.Caption = "当前为轨道片";
  116.                         txtLatLng.EditValue = string.Format("GMap距离{0},自己算的距离{1}", clickRoute.Distance, clickRoute.Tag);
  117.                         txtLatLng.AutoFillWidthInMenu = DevExpress.Utils.DefaultBoolean.True;
  118.                     }
  119.                 }
  120.             }
  121.         }
  122.         private void gmap_OnMarkerEnter(GMapMarker item)//设置选中的Marker
  123.         {
  124.             isMarkerEnter = true;
  125.             currentMarker = item;
  126.         }
  127.         private void gmap_OnMarkerLeave(GMapMarker item)//取消选中的Marker
  128.         {
  129.             isMarkerEnter = false;
  130.         }
  131.         private void gmap_MouseMove(object sender, MouseEventArgs e)//鼠标移动事件
  132.         {
  133.             PointLatLng p = gmap.FromLocalToLatLng(e.X, e.Y);
  134.             if (isMarkerEditable)//可编辑的情况下可以移动
  135.             {
  136.                 if (isMarkerEnter && isMouseDown)//如果按下且是Marker
  137.                 {
  138.                     isMarkerDrag = true;
  139.                 }
  140.                 if (!isMouseDown)//鼠标未按下
  141.                 {
  142.                     isMarkerDrag = false;//则图标不可移动
  143.                 }
  144.                 if (isMarkerDrag)//如果可移动
  145.                 {
  146.                     currentMarker.Position = p;//则位置随着鼠标移动
  147.                     string txt = currentMarker.ToolTipText;
  148.                     txt = string.Format("{0}:经度{1},纬度{2}", txt.Substring(0, txt.LastIndexOf(":")), p.Lng, p.Lat);
  150.                 }
  151.             }
  152.             txtMousePos.Caption = string.Format("鼠标位置:{0},{1}", p.Lat, p.Lng);
  153.         }
  154.         private void gmap_MouseUp(object sender, MouseEventArgs e)
  155.         {
  156.             isMouseDown = false;//鼠标未按下
  157.         }
  158.         bool isCalDistanceMode = false;//是否是测距模式
  159.         bool isMarkerEditable = false;//点是否可以编辑
  161.         //private GMapMarker clickMarker = null;
  162.         private GMarkerGoogleExt clickMarker = null;
  163.         private void gmap_OnMarkerClick(GMapMarker item, MouseEventArgs e)
  164.         {
  165.             SetPerfectPos(true, false, item.Overlay);
  166.             SetCurrentCustomAttribute(item.Overlay.Id);
  167.             var overlayname = item.Overlay.Id;
  168.             var attribute = customAttributes.Find(a => a.LineName == overlayname);
  169.             if (item is GMarkerGoogleExt)
  170.             {
  171.                 clickMarker = item as GMarkerGoogleExt;
  172.                 clickMarker.AddRect = !clickMarker.AddRect;
  173.                 SetTxtLatLng(clickMarker.Position);
  174.             }
  175.             gmap.Refresh();
  176.         }
  179.         private void chkbtnCalDisMode_CheckedChanged(object sender, EventArgs e)
  180.         {
  181.             isCalDistanceMode = chkbtnCalDisMode.Checked;
  182.         }
  184.         private void chkEditMode_CheckedChanged(object sender, EventArgs e)
  185.         {
  186.             isMarkerEditable = chkEditMode.Checked;
  187.         }