CLLocationManager问题

Question

我想获取单个位置，然后停止接收来自CLLocationManager的通知。

我是这样做的：

-(id)initWithDelegate:(id <GPSLocationDelegate>)aDelegate{
self = [super init];

if(self != nil) {
    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    delegate = aDelegate;

}
return self;
}

-(void)startUpdating{
    locationManager.distanceFilter = kCLDistanceFilterNone;
    locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;
    [locationManager startUpdatingLocation];
}

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    [locationManager stopUpdatingLocation];
    [delegate locationUpdate:newLocation];
}

问题是，即使我使用[locationManager stopUpdatingLocation];

在- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:中

我仍然会收到通知，你知道为什么会这样吗？

Answer 1

也许可以试试我的解决方案。我正在构建两个函数来处理LocationManger对象。第一个函数是startUpdates，用于处理开始更新位置。代码如下所示：

- (void)startUpdate
{
    if ([self locationManager])
    {
        [[self locationManager] stopUpdatingLocation];
    }
    else
    {
        self.locationManager = [[CLLocationManager alloc] init];
        [[self locationManager] setDelegate:self];
        [[self locationManager] setDesiredAccuracy:kCLLocationAccuracyBestForNavigation];
        [[self locationManager] setDistanceFilter:10.0];
    }

    [[self locationManager] startUpdatingLocation];
}

第二个函数是stopUpdate，用于处理CLLocationDelegate以停止更新位置。代码如下所示：

- (void)stopUpdate
{
    if ([self locationManager])
    {
        [[self locationManager] stopUpdatingLocation];
    }
}

因此，对于CLLocationManagerDelegate，应该是这样的：

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation
{    
    NSDate* eventDate = newLocation.timestamp;
    NSTimeInterval howRecent = [eventDate timeIntervalSinceNow];
    self.attempts++;

    if(firstPosition == NO)
    {
        if((howRecent < -2.0 || newLocation.horizontalAccuracy > 50.0) && ([self attempts] < 5))
        {
            // force an update, value is not good enough for starting Point            
            [self startUpdates];
            return;
        }
        else
        {
            firstPosition = YES;
            isReadyForReload = YES;
            tempNewLocation = newLocation;
            NSLog(@"## Latitude  : %f", tempNewLocation.coordinate.latitude);
            NSLog(@"## Longitude : %f", tempNewLocation.coordinate.longitude);
            [self stopUpdate];
        }
    }
}

在上面的函数中，我只正确地确定了更新位置的最佳位置。我希望我的回答能有所帮助，干杯。

Answer 2

我认为你的问题的原因在于距离过滤器。正如文档所说：

Use the value kCLDistanceFilterNone to be notified of all movements. The default value of this property is kCLDistanceFilterNone.，这样你就有了你设置的东西--连续更新。