在实际开发过程中，由于各种地图坐标之间的偏差，混用导致结果不正确，但如果搞清楚他们采用何种坐标，问题就迎刃而解了；
地球坐标(WGS84)
国际标准
例如：CLLocationManager
火星坐标 (GCJ-02)
中国标准
例如：iOS MKMapView、高德地图、国内google 、搜搜、阿里云
百度坐标 (BD-09)
百度标准
例如：百度 SDK，地图
以下给出相应的转换方法：
// a = 6378245.0, 1/f = 298.3
// b = a * (1 - f)
// ee = (a^2 - b^2) / a^2;
let a:Double = 6378245.0
let ee:Double = 0.00669342162296594323
letx_pi:Double=M_PI*3000.0/180.0
importCoreLocation
public extension CLLocation {
/// 从地图坐标转化到火星坐标
///
/// - Returns: CLLocation
func locationMarsFromEarth() -> CLLocation {
let (n_lat,n_lng) = CLLocation.transform_earth_from_mars(lat: self.coordinate.latitude, lng: self.coordinate.longitude)
let coord_2d = CLLocationCoordinate2D(latitude: n_lat + self.coordinate.latitude, longitude: n_lng + self.coordinate.longitude)
return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
}
/// 从火星坐标到地图坐标
///
/// - Returns: CLLocation
func locationEarthFromMars() -> CLLocation {
let (n_lat,n_lng) = CLLocation.transform_earth_from_mars(lat: self.coordinate.latitude, lng: self.coordinate.longitude)
let coord_2d = CLLocationCoordinate2D(latitude: self.coordinate.latitude - n_lat, longitude: self.coordinate.longitude - n_lng)
return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
}
/// 从火星坐标转化到百度坐标
///
/// - Returns: CLLocation
func locationBaiduFromMars() -> CLLocation {
let (n_lat,n_lng) = CLLocation.transform_mars_from_baidu(lat: self.coordinate.latitude, lng: self.coordinate.longitude)
letcoord_2d =CLLocationCoordinate2D(latitude: n_lat,longitude: n_lng)
return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
}
/// 从百度坐标到火星坐标
///
/// - Returns: CLLocation
func locationMarsFromBaidu() -> CLLocation {
let (n_lat,n_lng) = CLLocation.transform_baidu_from_mars(lat: self.coordinate.latitude, lng: self.coordinate.longitude)
letcoord_2d =CLLocationCoordinate2D(latitude: n_lat,longitude: n_lng)
return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
}
/// 从百度坐标到地图坐标
///
/// - Returns: CLLocation
func locationEarthFromBaidu() -> CLLocation {
let mars = self.locationMarsFromBaidu()
let (n_lat,n_lng) = CLLocation.transform_earth_from_mars(lat: mars.coordinate.latitude, lng: mars.coordinate.longitude)
let coord_2d = CLLocationCoordinate2D(latitude: self.coordinate.latitude - n_lat, longitude: self.coordinate.longitude - n_lng)
return CLLocation(coordinate: coord_2d, altitude: self.altitude, horizontalAccuracy: self.horizontalAccuracy, verticalAccuracy: self.horizontalAccuracy, course: self.course, speed: self.speed, timestamp: self.timestamp)
}
private class func transform_earth_from_mars(lat: Double, lng: Double) -> (Double, Double) {
if CLLocation.transform_sino_out_china(lat: lat, lng: lng) {
return(lat, lng)
}
vardLat =CLLocation.transform_earth_from_mars_lat(lng -105.0, lat -35.0)
vardLng =CLLocation.transform_earth_from_mars_lng(lng -105.0, lat -35.0)
letradLat = lat /180.0*M_PI
varmagic =sin(radLat)
magic =1-ee* magic * magic
letsqrtMagic:Double=sqrt(magic)
dLat = (dLat *180.0) / ((a* (1-ee)) / (magic * sqrtMagic) *M_PI)
dLng = (dLng *180.0) / (a/ sqrtMagic *cos(radLat) *M_PI)
return(dLat,dLng)
}
private class func transform_earth_from_mars_lat(_ x: Double,_ y: Double) -> Double {
varret:Double= -100.0+2.0* x +3.0* y +0.2* y * y +0.1* x * y +0.2*sqrt(fabs(x))
ret += (20.0*sin(6.0* x *M_PI) +20.0*sin(2.0* x *M_PI)) *2.0/3.0
ret += (20.0*sin(y *M_PI) +40.0*sin(y /3.0*M_PI)) *2.0/3.0
ret += (160.0*sin(y /12.0*M_PI) +320*sin(y *M_PI/30.0)) *2.0/3.0
returnret
}
private class func transform_earth_from_mars_lng(_ x: Double,_ y: Double) -> Double {
varret:Double=300.0+ x +2.0* y +0.1* x * x +0.1* x * y +0.1*sqrt(fabs(x))
ret += (20.0*sin(6.0* x *M_PI) +20.0*sin(2.0* x *M_PI)) *2.0/3.0
ret += (20.0*sin(x *M_PI) +40.0*sin(x /3.0*M_PI)) *2.0/3.0
ret += (150.0*sin(x /12.0*M_PI) +300.0*sin(x /30.0*M_PI)) *2.0/3.0
returnret
}
private class func transform_mars_from_baidu(lat: Double, lng: Double) -> (Double,Double) {
letx = lng , y = lat
letz =sqrt(x * x + y * y) +0.00002*sin(y *x_pi)
lettheta =atan2(y, x) +0.000003*cos(x *x_pi)
return(z *sin(theta) +0.006, z *cos(theta) +0.0065)
}
private class func transform_baidu_from_mars(lat: Double, lng: Double) -> (Double,Double) {
letx = lng -0.0065, y = lat -0.006
letz = sqrt(x * x + y * y) -0.00002*sin(y *x_pi)
lettheta =atan2(y, x) -0.000003*cos(x *x_pi)
return(z *sin(theta), z *cos(theta))
}
private class func transform_sino_out_china(lat: Double, lng: Double) -> Bool {
if(lng <72.004|| lng >137.8347) {
returntrue
}
if(lat <0.8293|| lat >55.8271) {
returntrue
}
return false
}
}
