计算wgs84球面两点的距离

private static IMap wgs84Map=null;public static double  getDis(IPoint p1,IPoint p2){  wgs84Map=new Map();  ISpatialReferenceFactory pF=new  SpatialReferencEnvironment();  IGeograohicCoordinateSystem pG=pF.CreateGeograohicCoordinateSystem((int)esriSRGeoType.esriSRGeoCS_1984);  wgs84Map.SpatialReference=pG;  wgs84Map.MapUnits=esriUnits.esriDecimalDegrees;  wgs84Map.DistanceUnits=esriUnits.esriKilometers;  return wgs84Map.ComputeDistance(p1,p2);}