我想知道如果CMMotionActivity发生变化,系统是否可以在后台唤醒应用程序,例如,如果用户在坐下后开始步行/跑步,我希望能够执行一些代码并安排本地通知.
有没有办法要求系统在后台唤醒我的应用程序？
编辑：通过查看reference,它似乎不可能(“[…]并且在您的应用程序被暂停时未提供更新.”),但也许还有另一种方式？
解决方法
我解决了这个问题,创建了一个后台计时器,并在名为method的选择器中检查活动类型.只需查看代码,以防它对您有用.我接受有关此的建议,更正和建议.
#define k_timer_time 10.0f
@property NSTimer *timer;
- (void) createBackGroundTimertocheckMotion{
// create new uibackgroundtask
__block uibackgroundtaskIdentifier bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
[[UIApplication sharedApplication] endBackgroundTask:bgTask];
bgTask = uibackgroundtaskInvalid;
}];
__weak __typeof(self) weakSelf = self;
// and create new timer with async call:
dispatch_async(dispatch_get_global_queue(disPATCH_QUEUE_PRIORITY_DEFAULT,0),^{
weakSelf.timer = [NSTimer scheduledTimerWithTimeInterval:k_timer_time target:self selector:@selector(onTick:) userInfo:nil repeats:YES];
weakSelf.timer.tolerance = 5;
[[NSRunLoop currentRunLoop] addTimer:weakSelf.timer forMode:NSDefaultRunLoopMode];
[[NSRunLoop currentRunLoop] run];
});
}
- (void) onTick:(NStimer*)timer{
if([CMMotionActivityManager isActivityAvailable])
{
__weak __typeof(self) weakSelf = self;
CMMotionActivityManager *cm = [[CMMotionActivityManager alloc] init];
CMpedometer *sc = [[CMpedometer alloc] init];
NSDate *Now = [NSDate date];
NSDate *last30Sec = [Now dateByAddingTimeInterval:-30];
[cm queryActivityStartingFromDate:last30Sec toDate:Now toQueue:[NSOperationQueue mainQueue] withHandler:^(NSArray *activities,NSError *error)
{
[activities enumerateObjectsUsingBlock:^(CMMotionActivity *a,NSUInteger idx,BOOL * _Nonnull stop) {
//Your stuff here
}];
}];
}
else
{
NSLog(@"Error accessing Motion data");
}
}