iOS版：針對特定地理區域位置警告用戶（緯度，經度）

Question

我試圖實現一個Geo location爲用戶的功能，我靜態設置latitude和longitude信息時，如果用戶的應用程序啓動在那個區域內，我正在顯示一條消息，「你已經到達辦公室」，否則「你正在外出」。爲了達到這個目的，我已經實現了下面的代碼，我嘗試了通過步驟和車輛四處移動，但是在兩種情況下，它總是顯示「您已經到達辦公室」，但是我離該位置2公里！我認爲問題在於CLLocationManager代表中地理數據的比較。

- (void) startUpdateUserLocation 
{ 
    if(!locationManager) 
     locationManager = [[CLLocationManager alloc] init]; 

    locationManager.delegate = self; 
    locationManager.distanceFilter = kCLDistanceFilterNone; 
    locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation; 

// [locationManager startUpdatingLocation]; 

    CLLocationCoordinate2D coord = CLLocationCoordinate2DMake(latitude, longitude); 

    CLRegion *region = [[CLRegion alloc] initCircularRegionWithCenter:coord radius:kCLDistanceFilterNone identifier:@"identifier"]; 
    [locationManager startMonitoringForRegion:region]; 
} 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    latitude = 23.076289; 
    longitude = 72.508129; 
} 

- (void) viewDidAppear:(BOOL)animated 
{ 
    [super viewDidAppear:animated]; 

    MKCoordinateRegion region; 
    region.center = mapView.userLocation.coordinate; 
    region.span = MKCoordinateSpanMake(0.25, 0.25); 
    region = [mapView regionThatFits:region]; 
    [mapView setRegion:region animated:YES]; 

    lblCurrentCoords.text = [NSString stringWithFormat:@"lat %f lon %f",mapView.userLocation.coordinate.latitude,mapView.userLocation.coordinate.longitude]; 

    [self startUpdateUserLocation]; 
} 

- (void)locationManager:(CLLocationManager *)manager 
didEnterRegion:(CLRegion *)region __OSX_AVAILABLE_STARTING(__MAC_10_7,__IPHONE_4_0) 
{ 
    [listOfPoints addObject:manager.location]; 
    [tablePoints reloadData]; 

    /* 
    * locationManager:didEnterRegion: 
    * 
    * Discussion: 
    * Invoked when the user enters a monitored region. This callback will be invoked for every allocated 
    * CLLocationManager instance with a non-nil delegate that implements this method. 
    */ 

    lblLocationStatus.text = @"You're in office area!..."; 
} 

- (void)locationManager:(CLLocationManager *)manager 
didExitRegion:(CLRegion *)region __OSX_AVAILABLE_STARTING(__MAC_10_7,__IPHONE_4_0) 
{ 
    /* 
    * locationManager:didExitRegion: 
    * 
    * Discussion: 
    * Invoked when the user exits a monitored region. This callback will be invoked for every allocated 
    * CLLocationManager instance with a non-nil delegate that implements this method. 
    */ 

    lblLocationStatus.text = @"You're going out from office area!..."; 
} 

- (void)locationManager:(CLLocationManager *)manager 
didStartMonitoringForRegion:(CLRegion *)region __OSX_AVAILABLE_STARTING(__MAC_TBD,__IPHONE_5_0) 
{ 
    /* 
    * locationManager:didStartMonitoringForRegion: 
    * 
    * Discussion: 
    * Invoked when a monitoring for a region started successfully. 
    */ 

    lblLocationStatus.text = @"Start monitoring..."; 
} 

- (void)locationManager:(CLLocationManager *)manager 
monitoringDidFailForRegion:(CLRegion *)region 
withError:(NSError *)error __OSX_AVAILABLE_STARTING(__MAC_10_7,__IPHONE_4_0) 
{ 
    /* 
    * locationManager:monitoringDidFailForRegion:withError: 
    * 
    * Discussion: 
    * Invoked when a region monitoring error has occurred. Error types are defined in "CLError.h". 
    */ 

    lblLocationStatus.text = @"Stop monitoring..."; 
} 

我正在努力完成以下工作！

1. 如果用戶進入地理位置，他應該是「alert」。 ---如何匹配位置？
2. 如果在該地理位置內移動，則代碼應該監視此活動！ ---需要設置所需的精度屬性？
3. 我希望我的代碼不斷地檢查用戶地理位置，我該怎麼做？ ---需要撥打NSTimer的功能？

我發現很多關於這個問題都問過同樣的問題，但沒有人找到答案！有人請指導我是否朝着正確的方向前進，因爲這段代碼沒有顯示出來！ :)

Answer 1

這聽起來像你應該使用區域監視，而不是告訴你什麼時候用戶進入或退出一個圓形區域。與startMonitoringForRegion:設置並執行CLLocationManagerDelegate方法

– locationManager:didEnterRegion: 
– locationManager:didExitRegion: 
– locationManager:monitoringDidFailForRegion:withError: 
– locationManager:didStartMonitoringForRegion: 

如果您有任何不好的位置數據來麻煩，請檢查CLLocation在locationManager:didUpdateLocations:或locationManager:didUpdateToLocation:fromLocation:歲。如果它超過60秒，請不要使用它。