根据经纬度计算距离

+(double)getDistanceWithOtherLatitde:(double)olat otherLongitude:(double)olon myLatitde:(double)mlat myLongitude:(double)mlon //计算出相聚多少米
{
    CLLocation*otherLocation=[[CLLocation alloc]initWithLatitude:olat longitude:olon];
    CLLocation*myLocation=[[CLLocation alloc]initWithLatitude:mlat longitude:mlon];
    CLLocationDistance meters=[otherLocation distanceFromLocation:myLocation];
    return meters;
}