.Net 中计算2个点之间的距离的方法，或者叫计算2个坐标，2个经纬度之间的距离。
代码如下：
1 /// <summary> 2 /// Calculates the distance between two geographics locations 3 /// </summary> 4 public static class GeoDistance 5 { 6 public static double Between(double latitude1, double longitude1, double latitude2, double longitude2, 7 DistanceUnits units = DistanceUnits.Kilometers) 8 { 9 double a1 = latitude1 * RadianConversionFactor; 10 double b1 = longitude1 * RadianConversionFactor; 11 double a2 = latitude2 * RadianConversionFactor; 12 double b2 = longitude2 * RadianConversionFactor; 13 14 double distance = 15 Math.Acos(Math.Cos(a1) * Math.Cos(b1) * Math.Cos(a2) * Math.Cos(b2) + 16 Math.Cos(a1) * Math.Sin(b1) * Math.Cos(a2) * Math.Sin(b2) + Math.Sin(a1) * Math.Sin(a2)) * DistanceConstants[units]; 17 18 return distance; 19 } 20 21 private const double RadianConversionFactor = Math.PI / 180; 22 23 private static readonly Dictionary<DistanceUnits, double> DistanceConstants = new Dictionary<DistanceUnits, double>(3) { 24 { DistanceUnits.Miles, 3963.1 }, 25 { DistanceUnits.NauticalMiles, 3443.9 }, 26 { DistanceUnits.Kilometers, 6378 } 27 }; 28 } 29 30 public enum DistanceUnits 31 { 32 Miles, 33 NauticalMiles, 34 Kilometers, 35 }
代码很简单，但是费了不少劲。就是还没测试效率怎么样。如果有高效的算法，请不要吝啬指教！！！