在每次发布应用程序时获取当前位置ios

Question

我正在开发iOS应用程序，我想在每次启动应用程序时加载用户的当前位置。

我已经在didFinishLaunchingWithOptions中编写了这段代码，但是当我第一次启动我的应用程序时，它仅提取一次用户位置。 （我测试我的应用程序在iOS版5秒7）

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { 

    locationManager = [[CLLocationManager alloc] init]; 

       locationManager.delegate = self; 
       if(IS_OS_8_OR_LATER){ 
        NSUInteger code = [CLLocationManager authorizationStatus]; 
        if (code == kCLAuthorizationStatusNotDetermined && ([locationManager respondsToSelector:@selector(requestAlwaysAuthorization)] || [locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)])) { 
         // choose one request according to your business. 
         if([[NSBundle mainBundle] objectForInfoDictionaryKey:@"NSLocationAlwaysUsageDescription"]){ 
          [locationManager requestAlwaysAuthorization]; 
         } else if([[NSBundle mainBundle] objectForInfoDictionaryKey:@"NSLocationWhenInUseUsageDescription"]) { 
          [locationManager requestWhenInUseAuthorization]; 
         } else { 
          NSLog(@"Info.plist does not contain NSLocationAlwaysUsageDescription or NSLocationWhenInUseUsageDescription"); 
         } 
        } 
       } 
       [locationManager startUpdatingLocation]; 


       ... 
       ... 
       ... 
} 

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 
{ 

    CLLocation *currentLocation = newLocation; 
    [locationManager stopUpdatingLocation]; 
} 

现在，当我去我家的位置发生改变，当我尝试打开我的应用程序不取回家位置，而不是它表明我的老位置（我的旧位置和本地位置有很大区别）

请帮助，并提前致谢。

Answer 1

我认为你正在寻找applicationWillEnterForeground或applicationDidBecomeActive，每次用户打开你的应用程序时都会调用它（'变为活动状态'）。

didFinishLaunchingWithOptions仅在应用程序初次启动时调用一次。

From the docs，状态转换事件的概述：

推出时间：

application:willFinishLaunchingWithOptions

application:didFinishLaunchingWithOptions

过渡到前台：

applicationDidBecomeActive

过渡到背景：

applicationDidEnterBackground

转变到不活动状态

applicationWillResignActive

applicationWillEnterForeground（转出的时调用（离开前台状态时调用。）背景状态）。

Ter mination：

applicationWillTerminate（仅在应用程序运行时调用。如果应用程序被暂停此方法不叫。）

Answer 2

编写代码在applicationDidBecomeActive。每次来自背景时都会调用它。

- (void)applicationDidBecomeActive:(UIApplication *)application { 
//Get Current Location 
    if ([CLLocationManager locationServicesEnabled]) 
    { 
     self.locationManager = [[CLLocationManager alloc] init]; 
     self.locationManager.delegate = self; 
     self.locationManager.pausesLocationUpdatesAutomatically = NO; 
     self.locationManager.desiredAccuracy = kCLLocationAccuracyBest; 
     // Check for iOS 8. Without this guard the code will crash with "unknown selector" on iOS 7. 
     if ([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) { 
      [self.locationManager requestAlwaysAuthorization]; 
     } 
     [self.locationManager startUpdatingLocation]; 
    } 
    else 
    { 
     NSLog(@"Location services are not enabled"); 
    } 
} 

#pragma mark -- Location Delegate Methods 

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations 
{ 
    CLLocation *location = [locations lastObject]; 
    if (location != nil)  
     NSLog(@"current lat:%f , currentLong:%f",location.coordinate.latitude,location.coordinate.longitude); 

    [manager stopUpdatingLocation]; 
} 

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

-(void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status 
{ 
    switch (status) { 
     case kCLAuthorizationStatusNotDetermined: 
     case kCLAuthorizationStatusRestricted: 
     case kCLAuthorizationStatusDenied: 
     { 
      // do some error handling 
     } 
      break; 
     default:{ 
      [self.locationManager startUpdatingLocation]; 
     } 
      break; 
    } 
}