//WGS-84 to GCJ-02
private void Wgs84ToGcj02()
{
if (Wgs84 == null || this.outOfChina(Wgs84))
{
Gcj02 = Wgs84;
}
var t = this.delta(Wgs84);
Gcj02.lng = t.lng + Wgs84.lng;
Gcj02.lat = t.lat + Wgs84.lat;
}
//GCJ-02 to WGS-84
private void Gcj02ToWgs84()
{
if (Gcj02 == null || this.outOfChina(Gcj02))
{
Wgs84 = Gcj02;
}
var t = this.delta(Gcj02);
Wgs84.lng = Gcj02.lng - t.lng;
Wgs84.lat = Gcj02.lat - t.lat;
}
private bool outOfChina(Gps _t)
{
if (_t.lng < 72.004 || _t.lng > 137.8347)
{
return(true);
}
if (_t.lat < 0.8293 || _t.lat > 55.8271)
{
return(true);
}
return(false);
}
private Gps delta(Gps t)
{
var a = 6378245.0; // a: 卫星椭球坐标投影到平面地图坐标系的投影因子。
var ee = 0.00669342162296594323; // ee: 椭球的偏心率。
var dLat = this.transformLat(t.lng - 105.0, t.lat - 35.0);
var dLng = this.transformLng(t.lng - 105.0, t.lat - 35.0);
var radLat = t.lat / 180.0 * PI;
var magic = Math.Sin(radLat);
magic = 1 - ee * magic * magic;
var sqrtMagic = Math.Sqrt(magic);
return(new Gps()
{
lat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * PI), lng = (dLng * 180.0) / (a / sqrtMagic * Math.Cos(radLat) * PI)
});
}
public GpsHelper(Gps _v, GpsType type)
{
if (type == GpsType.Wgs84)
{
Wgs84 = _v;
Wgs84ToDfm();
Wgs84ToGcj02();
Gcj02ToBd09();
}
else if (type == GpsType.Gcj02)
{
Gcj02 = _v;
Gcj02ToWgs84();
Wgs84ToDfm();
Gcj02ToBd09();
}
else if (type == GpsType.Bd09)
{
Bd09 = _v;
Bd09ToGcj02();
Gcj02ToWgs84();
Wgs84ToDfm();
}
}