在iOS中后台运行应用程序时将用户位置发送到服务器

Question

请帮我，我正在尝试将我当前的应用位置发送到服务器，而我的应用处于后台模式。

但是一段时间后，位置更新方法将停止以获取当前位置。

- (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);
     }];
}

我在我的应用中使用了后台抓取和位置更新。 也可以通过设置->功能将其打开。

但是，当我从xcode调试并在后台获取应用程序时，它可以正常工作，但是当我断开连接并对其进行测试时，它停止更新我的位置。

请帮助我。

Answer 1

似乎您正在使用受此示例启发的代码https://github.com/voyage11/Location

但是此示例将在10秒后停止位置更新，以节省电池寿命。 查看此评论

//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，如果配置正确，locationtracker还会创建一个计时器，以便在60秒内再次开始位置更新。

基本上，它会收集位置更新10秒钟，以过滤出最佳位置。 60秒后，位置更新将再次开始。 在上面的链接中，请参考LocationAppDelegate调用

//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];

该计时器导致位置更新的“重启”。