通过经纬度计算两个之间的距离

+(double)distanceBetweenOrderBy:(double)lat1 :(double)lat2 :(double)lng1 :(double)lng2{
CLLocation* curLocation = [[CLLocation alloc] initWithLatitude:lat1 longitude:lng1];
CLLocation* otherLocation = [[CLLocation alloc] initWithLatitude:lat2 longitude:lng2];
double distance  = [curLocation distanceFromLocation:otherLocation];
return distance;
}