在iOS中后台運行應用程序時將用戶位置發送到服務器

Question

請幫我，我正在嘗試將我當前的應用位置發送到服務器，而我的應用處於后台模式。

但是一段時間后，位置更新方法將停止以獲取當前位置。

- (void)startLocationTracking
{
    NSLog(@"startLocationTracking");

    if ([CLLocationManager locationServicesEnabled] == NO)
    {
        NSLog(@"locationServicesEnabled false");
        UIAlertView *servicesDisabledAlert = [[UIAlertView alloc] initWithTitle:@"Location Services Disabled" message:@"You currently have all location services for this device disabled" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [servicesDisabledAlert show];
    } else
    {
        CLAuthorizationStatus authorizationStatus= [CLLocationManager authorizationStatus];

        if(authorizationStatus == kCLAuthorizationStatusDenied || authorizationStatus == kCLAuthorizationStatusRestricted){
            NSLog(@"authorizationStatus failed");
        } else {
            NSLog(@"authorizationStatus authorized");
            CLLocationManager *locationManager = [LocationTracker sharedLocationManager];
            locationManager.delegate = self;
            locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
            locationManager.distanceFilter = kCLDistanceFilterNone;

            if(IS_OS_8_OR_LATER) {
              [locationManager requestAlwaysAuthorization];
            }
            [locationManager startUpdatingLocation];
            [locationManager startMonitoringSignificantLocationChanges];
        }
    }
}


- (void)stopLocationTracking {
    NSLog(@"stopLocationTracking");

    if (self.shareModel.timer) {
        [self.shareModel.timer invalidate];
        self.shareModel.timer = nil;
    }

    CLLocationManager *locationManager = [LocationTracker sharedLocationManager];
    [locationManager stopUpdatingLocation];
    [locationManager stopMonitoringSignificantLocationChanges];
}

#pragma mark - CLLocationManagerDelegate Methods

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations{

    NSLog(@"locationManager didUpdateLocations");

    for(int i=0;i<locations.count;i++){
        CLLocation * newLocation = [locations objectAtIndex:i];
        CLLocationCoordinate2D theLocation = newLocation.coordinate;
        CLLocationAccuracy theAccuracy = newLocation.horizontalAccuracy;

        NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow];

        if (locationAge > 30.0)
        {
            continue;
        }

        //Select only valid location and also location with good accuracy
        if(newLocation!=nil&&theAccuracy>0
           &&theAccuracy<2000
           &&(!(theLocation.latitude==0.0&&theLocation.longitude==0.0))){

            self.myLastLocation = theLocation;
            self.myLastLocationAccuracy= theAccuracy;

            NSMutableDictionary * dict = [[NSMutableDictionary alloc]init];
            [dict setObject:[NSNumber numberWithFloat:theLocation.latitude] forKey:@"latitude"];
            [dict setObject:[NSNumber numberWithFloat:theLocation.longitude] forKey:@"longitude"];
            [dict setObject:[NSNumber numberWithFloat:theAccuracy] forKey:@"theAccuracy"];

            //Add the vallid location with good accuracy into an array
            //Every 1 minute, I will select the best location based on accuracy and send to server
            [self.shareModel.myLocationArray addObject:dict];
        }
    }

    //If the timer still valid, return it (Will not run the code below)
    if (self.shareModel.timer) {
        return;
    }

    self.shareModel.bgTask = [BackgroundTaskManager sharedBackgroundTaskManager];
    [self.shareModel.bgTask beginNewBackgroundTask];

    //Restart the locationMaanger after 1 minute
    self.shareModel.timer = [NSTimer scheduledTimerWithTimeInterval:60 target:self
                                                           selector:@selector(restartLocationUpdates)
                                                           userInfo:nil
                                                            repeats:NO];

    //Will only stop the locationManager after 10 seconds, so that we can get some accurate locations
    //The location manager will only operate for 10 seconds to save battery
    if (self.shareModel.delay10Seconds) {
        [self.shareModel.delay10Seconds invalidate];
        self.shareModel.delay10Seconds = nil;
    }

    self.shareModel.delay10Seconds = [NSTimer scheduledTimerWithTimeInterval:10 target:self
                                                    selector:@selector(stopLocationDelayBy10Seconds)
                                                    userInfo:nil
                                                     repeats:NO];
}


//Stop the locationManager
-(void)stopLocationDelayBy10Seconds{
    CLLocationManager *locationManager = [LocationTracker sharedLocationManager];
    [locationManager stopUpdatingLocation];
    [locationManager stopMonitoringSignificantLocationChanges];

    NSLog(@"locationManager stop Updating after 10 seconds");
}


- (void)locationManager: (CLLocationManager *)manager didFailWithError: (NSError *)error
{
   NSLog(@"locationManager error:%@",error);
}


//Send the location to Server
- (void)updateLocationToServer {

    NSLog(@"updateLocationToServer");

    // Find the best location from the array based on accuracy
    NSMutableDictionary * myBestLocation = [[NSMutableDictionary alloc]init];

    for(int i=0;i<self.shareModel.myLocationArray.count;i++){
        NSMutableDictionary * currentLocation = [self.shareModel.myLocationArray objectAtIndex:i];

        if(i==0)
            myBestLocation = currentLocation;
        else{
            if([[currentLocation objectForKey:ACCURACY]floatValue]<=[[myBestLocation objectForKey:ACCURACY]floatValue]){
                myBestLocation = currentLocation;
            }
        }
    }
    NSLog(@"My Best location:%@",myBestLocation);

    //If the array is 0, get the last location
    //Sometimes due to network issue or unknown reason, you could not get the location during that  period, the best you can do is sending the last known location to the server
    if(self.shareModel.myLocationArray.count==0)
    {
        NSLog(@"Unable to get location, use the last known location");

        self.myLocation=self.myLastLocation;
        self.myLocationAccuracy=self.myLastLocationAccuracy;

    }else{
        CLLocationCoordinate2D theBestLocation;
        theBestLocation.latitude =[[myBestLocation objectForKey:LATITUDE]floatValue];
        theBestLocation.longitude =[[myBestLocation objectForKey:LONGITUDE]floatValue];
        self.myLocation=theBestLocation;
        self.myLocationAccuracy =[[myBestLocation objectForKey:ACCURACY]floatValue];
    }
    [self getUpdateLocation];
    NSLog(@"Send to Server: Latitude(%f) Longitude(%f) Accuracy(%f)",self.myLocation.latitude, self.myLocation.longitude,self.myLocationAccuracy);

    //TODO: Your code to send the self.myLocation and self.myLocationAccuracy to your server

    //After sending the location to the server successful, remember to clear the current array with the following code. It is to make sure that you clear up old location in the array and add the new locations from locationManager
    [self.shareModel.myLocationArray removeAllObjects];
    self.shareModel.myLocationArray = nil;
    self.shareModel.myLocationArray = [[NSMutableArray alloc]init];
}

-(void)getUpdateLocation
{
    NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];

    dataMobile = [currentDefaults valueForKey:@"mobile"];
    dataCode = [currentDefaults valueForKey:@"code"];

    strMobile = [self getDecryptionMobile];
    strCode = [self getDecryptionCode];

    strToken = [NSString stringWithFormat:@"%@%@%@",@"Apple",strMobile,strCode];

    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];

    NSDictionary *params = @ {@"function" :@"map/location/insert",@"childIdEnc":[currentDefaults valueForKey:@"childIdEnc"], @"phoneId" : [currentDefaults valueForKey:@"phoneId"], @"latitude": [NSString stringWithFormat:@"%f",self.myLocation.latitude], @"longitude": [NSString stringWithFormat:@"%f",self.myLocation.longitude]};
    NSLog(@"params %@",params);

    [manager POST:@"https://api.familyconnect.net/call/?debug=1" parameters:params
          success:^(AFHTTPRequestOperation *operation, id responseObject)
    {
        NSDictionary *jsonList = [NSJSONSerialization JSONObjectWithData:responseObject options:NSJSONReadingMutableContainers error:nil];
        NSLog(@"JSON: %@", jsonList);
    }
          failure:
     ^(AFHTTPRequestOperation *operation, NSError *error) {
         NSLog(@"Error: %@", error);
     }];
}

我在我的應用中使用了后台抓取和位置更新。 也可以通過設置->功能將其打開。

但是，當我從xcode調試並在后台獲取應用程序時，它可以正常工作，但是當我斷開連接並對其進行測試時，它停止更新我的位置。

請幫助我。

Answer 1

似乎您正在使用受此示例啟發的代碼https://github.com/voyage11/Location

但是此示例將在10秒后停止位置更新，以節省電池壽命。 查看此評論

//Will only stop the locationManager after 10 seconds, so that we can get some accurate locations
//The location manager will only operate for 10 seconds to save battery

但是，如果配置正確，locationtracker還會創建一個計時器，以便在60秒內再次開始位置更新。

基本上，它會收集位置更新10秒鍾，以過濾出最佳位置。 60秒后，位置更新將再次開始。 在上面的鏈接中，請參考LocationAppDelegate調用

//Send the best location to server every 60 seconds
//You may adjust the time interval depends on the need of your app.
NSTimeInterval time = 60.0;
self.locationUpdateTimer =
[NSTimer scheduledTimerWithTimeInterval:time
                                 target:self
                               selector:@selector(updateLocation)
                               userInfo:nil
                                repeats:YES];

該計時器導致位置更新的“重啟”。