locationManager = [[CLLocationManager alloc] init];locationManager.delegate =self;
//or whatever class you have for managing location

if(![CLLocationManager locationServicesEnabled] || ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusDenied))//判斷定位服務(wù)是否打開
{
   [InterfaceFuncation ShowAlertWithMessage:@"錯誤"AlertMessage:@"定位服務(wù)未打開\n保持在線需要后臺定位服務(wù)\n請到 設(shè)置－隱私 中打開定位服務(wù)"ButtonTitle:@"我錯了"];
   return;
}

@property(assign, nonatomic) UIBackgroundTaskIdentifier bgTask;
@property(strong, nonatomic) dispatch_block_t expirationHandler;
@property(assign, nonatomic)BOOL jobExpired;
@property(assign, nonatomic)BOOL background;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions
{
  UIApplication* app = [UIApplication sharedApplication];
  __weak NSUAAAIOSAppDelegate* selfRef =self;
  self.expirationHandler = ^{ //創(chuàng)建后臺自喚醒，當180s時間結(jié)束的時候系統(tǒng)會調(diào)用這里面的方法
    [app endBackgroundTask:selfRef.bgTask];
     selfRef.bgTask = UIBackgroundTaskInvalid;
     selfRef.bgTask = [app beginBackgroundTaskWithExpirationHandler:selfRef.expirationHandler];
     NSLog(@"Expired");
     selfRef.jobExpired =YES;
     while(selfRef.jobExpired)
     {
       // spin while we wait for the task to actually end.
       NSLog(@"等待180s循環(huán)進程的結(jié)束");
       [NSThreadsleepForTimeInterval:1];
     }
     // Restart the background task so we can run forever.
     [selfRef startBackgroundTask];
   };
   // Assume that we're in background at first since we get no notification from device that we're in background when
   // app launches immediately into background (i.e. when powering on the device or when the app is killed and restarted)
   [selfmonitorBatteryStateInBackground];
   locationManager = [[CLLocationManager alloc] init];
   locationManager.delegate =self;
   //[locationManager startUpdatingLocation];
   returnYES;
}
- (void)monitorBatteryStateInBackground
{
   self.background =YES;
   [selfstartBackgroundTask];
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
   // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
   NSLog(@"App is active");
   [UIApplication sharedApplication].applicationIconBadgeNumber=0;//取消應(yīng)用程序通知腳標
   [locationManager stopUpdatingLocation];
   self.background =NO;
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
   // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
   // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
   //if([self bgTask])
   if(isLogined)//當?shù)顷憼顟B(tài)才啟動后臺操作
   {
      self.bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:self.expirationHandler];
      NSLog(@"Entered background");
      [selfmonitorBatteryStateInBackground];
    }
}
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError*)error//當定位服務(wù)不可用出錯時，系統(tǒng)會自動調(diào)用該函數(shù)
{
   NSLog(@"定位服務(wù)出錯");
   if([error code]==kCLErrorDenied)//通過error的code來判斷錯誤類型
   {
      //Access denied by user
      NSLog(@"定位服務(wù)未打開");
      [InterfaceFuncation ShowAlertWithMessage:@"錯誤"AlertMessage:@"未開啟定位服務(wù)\n客戶端保持后臺功能需要調(diào)用系統(tǒng)的位置服務(wù)\n請到設(shè)置中打開位置服務(wù)"ButtonTitle:@"好"];
   }
}
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray*)locations//當用戶位置改變時，系統(tǒng)會自動調(diào)用，這里必須寫一點兒代碼，否則后臺時間刷新不管用
{
    NSLog(@"位置改變，必須做點兒事情才能刷新后臺時間");
    CLLocation *loc = [locations lastObject];
    //NSTimeInterval backgroundTimeRemaining = [[UIApplication sharedApplication] backgroundTimeRemaining];
    //NSLog(@"Background Time Remaining = %.02f Seconds",backgroundTimeRemaining);
    // Lat/Lon
    floatlatitudeMe = loc.coordinate.latitude;
    floatlongitudeMe = loc.coordinate.longitude;
}
- (void)startBackgroundTask
{
    NSLog(@"Restarting task");
    if(isLogined)//當?shù)顷憼顟B(tài)才進入后臺循環(huán)
    {
      // Start the long-running task.
      NSLog(@"登錄狀態(tài)后臺進程開啟");
      dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
          // When the job expires it still keeps running since we never exited it. Thus have the expiration handler
          // set a flag that the job expired and use that to exit the while loop and end the task.
          NSIntegercount=0;
          BOOLNoticeNoBackground=false;//只通知一次標志位
          BOOLFlushBackgroundTime=false;//只通知一次標志位
          locationManager.distanceFilter = kCLDistanceFilterNone;//任何運動均接受，任何運動將會觸發(fā)定位更新
          locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;//定位精度
          while(self.background && !self.jobExpired)
          {
              NSLog(@"進入后臺進程循環(huán)");
              [NSThreadsleepForTimeInterval:1];
              count++;
              if(count>60)//每60s進行一次開啟定位，刷新后臺時間
              {
                  count=0;
                  [locationManager startUpdatingLocation];
                  NSLog(@"開始位置服務(wù)");
                  [NSThreadsleepForTimeInterval:1];
                  [locationManager stopUpdatingLocation];
                  NSLog(@"停止位置服務(wù)");
                  FlushBackgroundTime=false;
               }
               if(!isLogined)//未登錄或者掉線狀態(tài)下關(guān)閉后臺
               {
                  NSLog(@"保持在線進程失效，退出后臺進程");
                  [InterfaceFuncation ShowLocalNotification:@"保持在線失效，登錄已被注銷，請重新登錄"];
                  [[UIApplication sharedApplication] endBackgroundTask:self.bgTask];
                  return;//退出循環(huán)
               }
               NSTimeIntervalbackgroundTimeRemaining = [[UIApplication sharedApplication] backgroundTimeRemaining];
               NSLog(@"Background Time Remaining = %.02f Seconds",backgroundTimeRemaining);
               if(backgroundTimeRemaining<30&&NoticeNoBackground==false)
               {
                   [InterfaceFuncation ShowLocalNotification:@"向系統(tǒng)申請長時間保持后臺失敗，請結(jié)束客戶端重新登錄"];
                   NoticeNoBackground=true;
               }
               //測試后臺時間刷新
               if(backgroundTimeRemaining>200&&FlushBackgroundTime==false)
               {
                  [[NSNotificationCenterdefaultCenter] postNotificationName:@"MessageUpdate"object:@"刷新后臺時間成功\n"];
                  FlushBackgroundTime=true;
                  //[InterfaceFuncation ShowLocalNotification:@"刷新后臺時間成功"];
                }
            }
            self.jobExpired =NO;
         });
     }
}