Question

是否可以将CLLocationManager Delegate方法放在Singleton类中，而该类是NSObject的子类而不是UIViewController？我想这样做，因为我喜欢从App Delegate调用Singleton并在UI加载时开始获取坐标

我有一个locationcontroller类，其中包含以下初始化代码

static locationController *sharedLocController = NULL;
+(locationController *) getSharedController
{   
    if (sharedLocController !=nil)
    {
        NSLog(@"locationController has already been created.....");
        return sharedLocController;
    }
    @synchronized(self)
    {
        if (sharedLocController == nil)
        {
            sharedLocController = [[self alloc] init];

        }
    }
    return sharedLocController;
}
//==============================================================================
+(id)alloc
{

    @synchronized([locationController class])
    {

        NSAssert(sharedLocController == nil, @"Attempted to allocate a second instance of a sharedLocMgr singleton.");
        sharedLocController = [super alloc];
        return sharedLocController;
    }
    return nil;
}
//==============================================================================
-(id)init
{
    self = [super init];

    if(sharedLocController !=nil)
    {

        if(!self.locMgr)
        {
            [self initLocationManager];

        }
    }



    return sharedLocController;
}
//==============================================================================
-(void)initLocationManager
{


    self.locMgr = [[CLLocationManager alloc] init];

    self.locMgr.delegate = self;
    self.locMgr.distanceFilter = kCLDistanceFilterNone;
    self.locMgr.desiredAccuracy = kCLLocationAccuracyBest;
    [self.locMgr startUpdatingLocation];
    NSLog(@"location manager object %@", locMgr);
}

问题是self.locMgr对象始终为null。感谢

Answer 1

是的，可以将它们放在NSObject子类中，这可能是一个单例。我用的是：

@interface MyCLController : NSObject <CLLocationManagerDelegate> {
    CLLocationManager *locationManager;
}

...

@end

虽然以防它不是单身人士。

Answer 2

摆脱你的alloc函数。它没有必要，并且返回nil，这意味着在nil指针上调用此init调用：

sharedLocController = [[self alloc] init];

CLLocationManager始终为null -Delegate实现是一个Singleton类（NSObject的子类而不是UIViewController的子类）

2 个答案: