c# 基于GMap.NET实现电子围栏功能（WPF版）

GMapMarker maker = new GMapMarker(ptLatLng);
 //UserControlFence用户自定控件
 _ctrlCurrentFence = new UserControlFence() { Marker = maker, MapCtrl = MainMap };
 _ctrlCurrentFence.FenceInfo = CreateFenceInfoModel();

 maker.Shape = _ctrlCurrentFence;
 this.MainMap.Markers.Add(maker);

public class GMapMarker : INotifyPropertyChanged
{
    public object Tag;
 
    public GMapMarker(PointLatLng pos);
 
    public UIElement Shape { get; set; }
    public PointLatLng Position { get; set; }
    public GMapControl Map { get; }
    public Point Offset { get; set; }
    public int LocalPositionX { get; }
    public int LocalPositionY { get; }
    public int ZIndex { get; set; }
 
    public event PropertyChangedEventHandler PropertyChanged;
 
    public virtual void Clear();
    protected void OnPropertyChanged(string name);
    protected void OnPropertyChanged(PropertyChangedEventArgs name);
}

Point ToCtrlPoint(PointLatLng gpsPoint)
  {
   //转换成GMap.NET控件坐标
   GPoint ptOfMapCtrl = MapCtrl.FromLatLngToLocal(gpsPoint);

   //GMap.NET控件坐标要转换成 控件相对于直接父面板的坐标
   Point ptToMapCtrl2 = new Point(ptOfMapCtrl.X, ptOfMapCtrl.Y);
   //转成屏幕坐标
   Point ptOfScreen = MapCtrl.PointToScreen(ptToMapCtrl2);
   //转换成相对于gridRoot的坐标
   Point ptOfParentPanel = gridRoot.PointFromScreen(ptOfScreen);

   return ptOfParentPanel;
  }

private PathGeometry CreatPath()
  {
   if (_listPoints.Count <= 1)
   {
    PathRouteLine.Data = null;
    return null;
   }

   List<Point> listPt = ListWndPoint;

   PathFigure pathFigure = new PathFigure();
   pathFigure.StartPoint = listPt[0]; //起始点
   pathFigure.IsClosed = true;

   for (int i = 1; i < listPt.Count; i++)
   {
    //加入线段
    LineSegment line = new LineSegment() { Point = listPt[i] };
    pathFigure.Segments.Add(line);
   }

   PathGeometry geometry = new PathGeometry();
   geometry.Figures.Add(pathFigure);
   return geometry;
  }

private bool IsInFence(PointLatLng gpsPoint)
  {
   if (_listPoints.Count <= 2)
    return false;
   Point ptWnd = ToCtrlPoint(gpsPoint);

   HitTestResult result = VisualTreeHelper.HitTest(gridRoot, ptWnd);
   if (result == null || result.VisualHit==null)
    return false;

   bool hit = result.VisualHit == PathRouteLineInner;
   return hit;
  }

private bool IsInFence2(PointLatLng gpsPoint)
  {
   double rate = 100000; //由于float精度问题。对坐标放大处理，否则误差会很大。
   System.Drawing.Drawing2D.GraphicsPath pointPath = new System.Drawing.Drawing2D.GraphicsPath();
   System.Drawing.PointF[] points = _listPoints.Select(o => new System.Drawing.PointF((float)(o.Lng * rate), (float)(o.Lat * rate))).ToArray();
   pointPath.AddLines(points);
   pointPath.CloseFigure();
    
   System.Drawing.Region region = new System.Drawing.Region(pointPath);
   System.Drawing.PointF ptHit = new System.Drawing.PointF((float)(gpsPoint.Lng * rate), (float)(gpsPoint.Lat * rate));
   bool visible = region.IsVisible(ptHit);
   return visible;
  }

private bool IsInFence3(PointLatLng gpsPoint)
  {
   int count = _listPoints.Count;
   if (count < 3)
   {
    return false;
   }

   bool result = false;
   for (int i = 0, j = count-1; i < count; i++)
   {
    var p1 = _listPoints[i];
    var p2 = _listPoints[j];

    if (p1.Lat < gpsPoint.Lat && p2.Lat >= gpsPoint.Lat || p2.Lat < gpsPoint.Lat && p1.Lat >= gpsPoint.Lat)
    {
     if (p1.Lng + (gpsPoint.Lat - p1.Lat) / (p2.Lat - p1.Lat) * (p2.Lng - p1.Lng) < gpsPoint.Lng)
     {
      result = !result;
     }
    }
    j = i;
   }
   return result;
  }