wgs84到gcj02

using System;namespace Navi{ class EvilTransform {

const double pi = 3.14159265358979324; 

// // Krasovsky 1940 // // a = 6378245.0, 1/f = 298.3 // b = a * (1 - f) // ee = (a^2 - b^2) / a^2; 

const double a = 6378245.0; 

const double ee = 0.00669342162296594323; 

// // World Geodetic System ==> Mars Geodetic System 

public static void transform(double wgLat, double wgLon, out double mgLat, out double mgLon) {

 if (outOfChina(wgLat, wgLon)) { 

mgLat = wgLat; mgLon = wgLon; return; 

} 

double dLat = transformLat(wgLon - 105.0, wgLat - 35.0); 

double dLon = transformLon(wgLon - 105.0, wgLat - 35.0); 

double radLat = wgLat / 180.0 * pi; 

double magic = Math.Sin(radLat); 

magic = 1 - ee * magic * magic; 

double sqrtMagic = Math.Sqrt(magic); 

dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi); 

dLon = (dLon * 180.0) / (a / sqrtMagic * Math.Cos(radLat) * pi); 

mgLat = wgLat + dLat; mgLon = wgLon + dLon; 

} 

static bool outOfChina(double lat, double lon) { 

if (lon < 72.004 || lon > 137.8347) 

return true; 

if (lat < 0.8293 || lat > 55.8271) 

return true; 

return false; 

} 

static double transformLat(double x, double y) {

 double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.Sqrt(Math.Abs(x)); 

ret += (20.0 * Math.Sin(6.0 * x * pi) + 20.0 * Math.Sin(2.0 * x * pi)) * 2.0 / 3.0; 

ret += (20.0 * Math.Sin(y * pi) + 40.0 * Math.Sin(y / 3.0 * pi)) * 2.0 / 3.0; 

ret += (160.0 * Math.Sin(y / 12.0 * pi) + 320 * Math.Sin(y * pi / 30.0)) * 2.0 / 3.0; 

return ret; 

} 

static double transformLon(double x, double y) { 

double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.Sqrt(Math.Abs(x));

 ret += (20.0 * Math.Sin(6.0 * x * pi) + 20.0 * Math.Sin(2.0 * x * pi)) * 2.0 / 3.0;

 ret += (20.0 * Math.Sin(x * pi) + 40.0 * Math.Sin(x / 3.0 * pi)) * 2.0 / 3.0; 

ret += (150.0 * Math.Sin(x / 12.0 * pi) + 300.0 * Math.Sin(x / 30.0 * pi)) * 2.0 / 3.0; 

return ret;

 } 

}

}

参考 https://on4wp7.codeplex.com/SourceControl/changeset/view/21483#353936