MapKit计算两个经纬度之间的距离多少M
CLLocationManager *locmanager = [[CLLocationManager alloc]init];//先定义一个cllocationmanager的实例
[locmanager setDelegate:self]; //设置代理为本身
[locmanager setDesiredAccuracy:kCLLocationAccuracyBest];//设置精确度为最准确
[locmanager startUpdatingLocation];//更新 location

//定义一个新的CLLocation实例，下面会取得user location 和这个新的地点间的距离
CLLocation * newLocation = [[CLLocation alloc]initWithLatitude:32.0206410 longitude:118.7889040];
NSLog(@"currenet:%@",[locmanager location]);

//关键就在这里，取得两个cllocation间的距离，单位是m
NSLog(@"%@",[NSString stringWithFormat:@"%0.2f km",[[locmanager location] distanceFromLocation:newLocation]/1000]);

// CLLocationDistance newDistance = [[locmanager location] distanceFromLocation:newLocation];