Iphone 距离位置似乎不起作用

在应用程序中，我需要计算两点之间的距离。我就是这样做的

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation{
    NSLog(@"updating");
     //Getting my concerts
    arrConcerten = [matches mutableCopy];

       for (Event *concert in arrConcerten) {
            CLLocation *restaurnatLoc = [[CLLocation alloc] initWithLatitude:[concert.eve_latitude floatValue] longitude:[concert.eve_longitude floatValue]];

            CLLocationDistance meters = [restaurnatLoc distanceFromLocation:newLocation];
            NSLog(@"meters are %f",meters);
            if(meters > 5000){
                [locationManager2 stopUpdatingLocation];
                NSString *message2 = [NSString stringWithFormat:@"Long = %f and lat= %f and Concert Lat = %f and long = %f",newLocation.coordinate.longitude,newLocation.coordinate.latitude,[concert.eve_latitude floatValue],[concert.eve_longitude floatValue]];
                NSLog(@"%@",message2);
            }else{

                NSLog(@"too far away");
            }

        }
    }

这是我的日志上写的

2013-10-17 15:57:23.518 Domino[7468:907] meters are 7973.753294
2013-10-17 15:57:23.520 Domino[7468:907] Long = 5.621456 and lat= 51.097340 and Concert Lat = 51.038139 and long = 5.557330
2013-10-17 15:57:23.896 Domino[7468:907] meters are 27850.874245
2013-10-17 15:57:23.899 Domino[7468:907] Long = 5.621456 and lat= 51.097340 and Concert Lat = 50.860332 and long = 5.493722

---

正如您所看到的，这些位置彼此很近。但它仍然说我们离得太远了。有人能帮我吗？

你为什么要用这个：

如果超过5000米：做点什么，离得太远吗？我不懂逻辑。如果距离太远，那就超过5000米。因此，我认为：

  - (void)locationManager:(CLLocationManager *)manager
        didUpdateToLocation:(CLLocation *)newLocation
               fromLocation:(CLLocation *)oldLocation{
        NSLog(@"updating");
         //Getting my concerts
        arrConcerten = [matches mutableCopy];

       for (Event *concert in arrConcerten) {
            CLLocation *restaurnatLoc = [[CLLocation alloc] initWithLatitude:[concert.eve_latitude floatValue] longitude:[concert.eve_longitude floatValue]];

            CLLocationDistance meters = [restaurnatLoc distanceFromLocation:newLocation];
            NSLog(@"meters are %f",meters);
            if(meters <= 5000){
                [locationManager2 stopUpdatingLocation];
                NSString *message2 = [NSString stringWithFormat:@"Long = %f and lat= %f and Concert Lat = %f and long = %f",newLocation.coordinate.longitude,newLocation.coordinate.latitude,[concert.eve_latitude floatValue],[concert.eve_longitude floatValue]];
                NSLog(@"%@",message2);
            }else{

                NSLog(@"too far away");
            }

        }
    }

还有一件非常重要的事：

该方法通过跟踪测量两个位置之间的距离 它们之间沿着地球曲率的一条线。这个 生成的圆弧是平滑曲线，不考虑 两个位置之间的具体高度变化。 从

距离距离位置测量“空中”距离，而不是逐圈测量。

以下是解决方案-

-(NSString *)getDistance:(NSDictionary *)dicVal{
    CLLocation *pinLocation = [[CLLocation alloc] initWithLatitude:[[dicVal valueForKey:@"latitude"] doubleValue] longitude:[[dicVal valueForKey:@"longitude"] doubleValue]];

    CLLocation *userLocation = [[CLLocation alloc] initWithLatitude:appDelegate.userLocation.latitude longitude:appDelegate.userLocation.longitude];

    CLLocationDistance distance = [pinLocation distanceFromLocation:userLocation];
    NSString *dist=[NSString stringWithFormat:@"%4.0f %@", distance/1000,NSLocalizedString(@"KM", nil)];
    return dist;
}

---

是的，这只是分配的问题，您必须在每次

cllocation

管理器分配，如下所示：

LocationManager = [[[CLLocationManager alloc] init] autorelease];
LocationManager.delegate = self;
LocationManager.desiredAccuracy = kCLLocationAccuracyBest;
LocationManager.distanceFilter = kCLDistanceFilterNone;
[LocationManager startUpdatingLocation];
CLLocation *location = [LocationManager location];
CLLocationCoordinate2D coordinate1 = [location coordinate];


CLLocation *currentLoc = [[CLLocation alloc] initWithLatitude:coordinate1.latitude longitude:coordinate1.longitude];
CLLocation *restaurnatLoc = [[CLLocation alloc] initWithLatitude:l@"Your latitude not current" longitude:@"Your longitude not current'];
CLLocationDistance meters = [restaurnatLoc distanceFromLocation:currentLoc];    


if (meters > 1000)
{
    Distancelbl.text=[NSString stringWithFormat: @"You are Away %.2f Km",meters];
}
else{
    Distancelbl.text=[NSString stringWithFormat: @"You are Away %.2f Mtr",meters];
}

---

`

我看他们好像不在一起，你为什么这么说？也许

if（meters>5000）

应该

if（meters>5000）

如果（meters）你试过把音乐会的水平面视为双倍而不是浮点数吗？浮点数会截断数值，这可能会导致你看到的问题。

LocationManager = [[[CLLocationManager alloc] init] autorelease];
LocationManager.delegate = self;
LocationManager.desiredAccuracy = kCLLocationAccuracyBest;
LocationManager.distanceFilter = kCLDistanceFilterNone;
[LocationManager startUpdatingLocation];
CLLocation *location = [LocationManager location];
CLLocationCoordinate2D coordinate1 = [location coordinate];


CLLocation *currentLoc = [[CLLocation alloc] initWithLatitude:coordinate1.latitude longitude:coordinate1.longitude];
CLLocation *restaurnatLoc = [[CLLocation alloc] initWithLatitude:l@"Your latitude not current" longitude:@"Your longitude not current'];
CLLocationDistance meters = [restaurnatLoc distanceFromLocation:currentLoc];    


if (meters > 1000)
{
    Distancelbl.text=[NSString stringWithFormat: @"You are Away %.2f Km",meters];
}
else{
    Distancelbl.text=[NSString stringWithFormat: @"You are Away %.2f Mtr",meters];
}