CLLocation *location1 = [[CLLocation alloc] initWithLatitude:self.mapView.userLocation.coordinate.latitude longitude:self.mapView.userLocation.coordinate.longitude];
    CLLocation *location2 = [[CLLocation alloc] initWithLatitude:[item.latitude doubleValue] longitude:[item.longitude doubleValue]];
    CLLocationDistance distance = [location1 distanceFromLocation:location2];