public static ChinaArea GetNearPosition(MapPoint point)
{
var key = Thread.CurrentThread.ManagedThreadId;
List <ChinaArea> list = null;
ChinaArea minitem = null;
var min = double.MaxValue;
var radlat = Rad(point.Y);
var radlon = Rad(point.X);
if (PositionDic.TryGetValue(key, out list))
{
list = list.Select(p => p).ToList();
foreach (var item in list)
{
if (item is Province)
{
var cities = (item as Province).Cities;
if (cities == null)
{
foreach (var pts in item.MapPointsList)
{
foreach (var pt in pts)
{
var dis = CalDistance2(radlat, radlon, Rad(pt.Y), Rad(pt.X));
if (dis < min)
{
min = dis;
minitem = item;
}
}
}
continue;
}
foreach (var city in cities)
{
var ct = city.Position(point);
if (ct != null)
{
return(ct);
}
foreach (var pts in city.MapPointsList)
{
foreach (var pt in pts)
{
var dis = CalDistance2(radlat, radlon, Rad(pt.Y), Rad(pt.X));
if (dis < min)
{
min = dis;
minitem = city;
}
}
}
}
}
}
if (min < 100000)
{
return(minitem);
}
return(null);
}
else
{
return(null);
}
}
/// <summary>
/// 判断一个点是否在多边形区域内
/// </summary>
/// <param name="points"></param>
/// <param name="point"></param>
/// <returns></returns>
public bool IsInArea(MapPoint[] points, double minxscral, double minyscral, MapPoint point)
{
if (points == null || points.Length < 2)
{
return(false);
}
List <double> ylist = new List <double>();
List <double> xlist = new List <double>();
MapPoint p1 = null, p2 = null;
double crossX = double.MinValue, crossY = double.MinValue;
for (int i = 0; i < points.Length - 1; i++)
{
p1 = points[i];
p2 = points[i + 1];
if (minxscral == 0 || Math.Abs(p1.X - point.X) <= minxscral)
{
if ((p1.X <= point.X && point.X <= p2.X) || (p2.X <= point.X && point.X <= p1.X))
{
if (p1.X != p2.X)
{
crossY = p1.Y + ((p2.Y - p1.Y) / Math.Abs(p2.X - p1.X)) * Math.Abs(p1.X - point.X);
}
else
{
if ((p1.Y - point.Y) * (p2.Y - point.Y) <= 0)
{
crossY = point.Y;
}
else
{
crossY = p1.Y + (p2.Y - p1.Y) / 2;
}
}
ylist.Add(crossY);
}
}
if (minyscral == 0 || Math.Abs(p1.Y - point.Y) <= minyscral)
{
if ((p1.Y <= point.Y && p2.Y >= point.Y) || (p2.Y <= point.Y && p1.Y >= point.Y))
{
if (p1.Y != p2.Y)
{
crossX = p1.X + (p2.X - p1.X) / Math.Abs(p2.Y - p1.Y) * Math.Abs(p1.Y - point.Y);
}
else
{
if ((p1.X - point.X) * (p2.X - point.X) <= 0)
{
crossX = point.X;
}
else
{
crossX = p1.X + (p2.X - p1.X) / 2;
}
}
xlist.Add(crossX);
}
}
}
if (xlist.Count == 0 || ylist.Count == 0)
{
return(false);
}
xlist = xlist.Distinct().OrderBy(p => p).ToList();
ylist = ylist.Distinct().OrderBy(p => p).ToList();
for (int i = 0; i < xlist.Count; i++)
{
var curr = xlist[i];
if (point.X < curr)
{
if (i % 2 == 0)
{
return(false);
}
else
{
break;
}
}
else if (i == xlist.Count - 1 && point.X > curr)
{
return(false);
}
}
for (int j = 0; j < ylist.Count; j++)
{
var curr = ylist[j];
if (point.Y < curr)
{
if (j % 2 == 0)
{
return(false);
}
else
{
return(true);
}
}
else if (j == ylist.Count - 1 && point.Y > curr)
{
return(false);
}
}
return(true);
}