这在前台下工作得很好,但是当应用转到后台时,操作系统会在 30 分钟到一小时后关闭它。我希望应用程序能在后台至少获取 8 小时的更新。
此外,该应用程序每小时使用约 10% 的电池电量。这是否与应用程序在后台被关闭有关?如果是这样,那么我该如何解决电池问题?否则,有人能告诉我问题出在哪里吗?
以下是设备的崩溃日志:
Exception Type: 00000020
Exception Codes: 0x000000008badf00d
Exception Note: SIMULATED (this is NOT a crash)
Highlighted by Thread: 2
Application Specific Information:
<BKNewProcess: 0x17e74840; com.app.app; pid: 560; hostpid: -1> has active assertions beyond permitted time:
{(
<BKProcessAssertion: 0x17d78740> id: 560-C9E81E97-90D9-4F95-871E-3DC53372F302 name: Called by UIKit, from <redacted> process: <BKNewProcess: 0x17e74840; com.app.example; pid: 560; hostpid: -1> permittedBackgroundDuration: 180.000000 reason: finishTask owner pid:560 preventSuspend preventIdleSleep preventSuspendOnSleep ,
<BKProcessAssertion: 0x17e6a870> id: 560-BD7B29FC-DABC-42FF-AF17-B277BDB1C59D name: Called by UIKit, from <redacted> process: <BKNewProcess: 0x17e74840; com.app.example; pid: 560; hostpid: -1> permittedBackgroundDuration: 180.000000 reason: finishTask owner pid:560 preventSuspend preventIdleSleep preventSuspendOnSleep
)}
对于后台任务,我使用以下函数:
func backgroundTask(){
var application=UIApplication.sharedApplication()
var background_task: UIBackgroundTaskIdentifier?
background_task = application.beginBackgroundTaskWithExpirationHandler({() -> Void in
application.endBackgroundTask(background_task!)
background_task = UIBackgroundTaskInvalid
})
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {() -> Void in
//run the app without startUpdatingLocation. backgroundTimeRemaining decremented from 600.00
self.locationManager.startUpdatingLocation()
while (true) {
//backgroundTimeRemaining time does not go down.
print("Background time Remaining: \(UIApplication.sharedApplication().backgroundTimeRemaining)")
NSThread.sleepForTimeInterval(1)
break
//wait for 1 sec
}
application.endBackgroundTask(background_task!)
background_task = UIBackgroundTaskInvalid
})
}