iOS的不是典型的背景定位跟踪计时器问题 [英] iOS Not the typical background location tracking timer issue
问题描述
我正在开发一个跟踪在后台用户的位置的示例应用程序，但我不想离开这个位置服务始终处于启用状态，但东西在我的计时器工作不正常。
i'm developing a sample app that tracks the user's position in background, but i don't want to leave the location service always enabled, but something in my timer does not behave properly.
我的想法是，每x分钟，服务的推移，当它有一个正确的新位置被再次释放，现在被设置为10秒的时间来进行测试。 （重大LocationChange没有的伎俩，没有足够的accurated）
My idea was that every x minutes, the service goes on, and when it have a correct new location it is released again, now is set to 10 seconds just for testing. (Significant LocationChange did not the trick, not accurated enough)
我正在寻找的人（的iOS开发中心+计算器），发现新后台定位功能，可让您将背景下，使用beginBackgroundTaskWithExpirationHandler，几个街区后，在运行10分钟code和一个计时器。
I was searching a lot (iOS Dev center + StackOverflow) and found the "new" background location features, that allows you to run code over 10 minutes after going to background, using beginBackgroundTaskWithExpirationHandler, a few blocks, and a timer.
我设置背景模式，定位与现在我认为我没有需要处理的背景时（首先我想每15-20秒的位置）结束
I set the background mode to Location and by now i think i don't need to handle the end of the background time (first i want to get a location every 15-20 seconds)
在code正在精，而是：
the code is working "fine" but:
- 定时器有时火灾，有时不会。
- 当计时器火灾，它需要至少10分钟做到这一点。
- 在OS一些随机的动作（如进入搜索桌面）似乎estimulate计时器射击（不知道这一点，我不知道它是如何可能的，但它是...）
和通过在code将是另外一个问题。
And by over the code will be another qüestion.
appdelegates的方法：
appdelegates's methods:
// applicationDidEnterBackground
- (void)applicationDidEnterBackground:(UIApplication *)application{
NSLog(@"to background");
UIApplication* app = [UIApplication sharedApplication];
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}];
// Start the long-running task and return immediately.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// Do the work associated with the task.
_triggertimer = nil;
[self initTimer];
});
NSLog(@"backgroundTimeRemaining: %.0f", [[UIApplication sharedApplication] backgroundTimeRemaining]);}
// initTimer
- (void) initTimer{
NSLog(@"InitTimer ");
UIApplication *app = [UIApplication sharedApplication];
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
_triggertimer = [NSTimer scheduledTimerWithTimeInterval:10.0
target:self
selector:@selector(checkUpdates:)
userInfo:nil
repeats:YES];
[[NSRunLoop currentRunLoop] addTimer:_triggertimer forMode:NSDefaultRunLoopMode] ;
[[NSRunLoop currentRunLoop] run];
}];}
// checkUpdates
- (void)checkUpdates:(NSTimer *)timer{
NSLog(@"CheckUpdates ");
UIApplication* app = [UIApplication sharedApplication];
if (nil == _locationManager) _locationManager = [[CLLocationManager alloc] init];
_locationManager.delegate = self;
_locationManager.distanceFilter = 10;
_locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;
[_locationManager startUpdatingLocation];
[_locationManager startMonitoringSignificantLocationChanges];
double remaining = app.backgroundTimeRemaining;
NSLog(@"Reminaing %f", remaining);}
我试过很多东西，试图解决这个问题，也许我搞砸或错过了什么？你看到了什么？也许有些概念错误，我想介绍自己的块，我不域他们还¬¬
I tried lots of thing to try to fix this and maybe i messed or missed something... What do you see? maybe some concept errors, i'm trying to introduce myself to the blocks and I don't domain them yet ¬¬
顺便说一句，为什么所有的codeS我找到包含此与做任何事情之前的 beginBackgroundTaskWithExpirationHandler
By the way,why all the codes i've found contains this before doing anything with beginBackgroundTaskWithExpirationHandler?
bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
[app endBackgroundTask:bgTask];
bgTask = UIBackgroundTaskInvalid;
}];
我认为这是采取的背景是600秒...但我不知道！
I thought that this is for taking that 600 seconds of background... but i'm not sure!
推荐答案
好吧，问题是，我是叫beginBackgroundTaskWithExpirationHandler两次，一次在 ApplicationDidEnterBackground ，另一个里面的 initTimer ...
Ok, the problem was that i was calling beginBackgroundTaskWithExpirationHandler twice, one in ApplicationDidEnterBackground and another one inside initTimer...
这篇关于iOS的不是典型的背景定位跟踪计时器问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
