AE求两点间距离的一种方法IProximityOperator

IPoint pt1,pt2;

IProximityOperator pro = pt1as IProximityOperator;

double len = pro.ReturnDistance(pt2);//得到的单位是当前地图单位

//转化为其它单位
double len = _unitConverter.ConvertUnits(len, esriUnits.esriDecimalDegrees, esriUnits.esriMeters);