objective-c - Xcode 4 中的地理围栏，didEnterRegion 提供了多个回调

Question

我正在尝试基于地理围栏在 Xcode 4 中创建一个应用程序。当进入具有特定中心坐标和以米为单位的特定半径的区域时，应用程序将通知用户。我所有的区域都保存在 p 列表中。但是，我得到了多个回调，并且调用了比我想要的更多的位置（即，即使不在正确位置的位置也被调用。下面你可以看到我们的代码。我还添加了一个 kml 层，你可以忽略它，因为它无关与围栏。我的 p-list 是一个数组，包含 20 个类型为字典的项目，键是标题、纬度、经度和半径。半径设置为 50 米。

视图控制器.h

#import "ViewController.h"
#import <CoreLocation/CoreLocation.h>

@implementation ViewController
@synthesize coordinateLabel;
@synthesize mapView;

CLLocationManager *_locationManager;
NSArray *_regionArray;

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self initializeMap];
    [self initializeLocationManager];
    NSArray *geofences = [self buildGeofenceData];
    [self initializeRegionMonitoring:geofences];
    [self initializeLocationUpdates];
}

- (void)viewDidUnload
{
    [self setCoordinateLabel:nil];
    [self setMapView:nil];
    [super viewDidUnload];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

- (void)initializeMap {
    CLLocationCoordinate2D initialCoordinate;
    initialCoordinate.latitude = 41.88072;
    initialCoordinate.longitude = -87.67429;

    [self.mapView setRegion:MKCoordinateRegionMakeWithDistance(initialCoordinate, 400, 400) animated:YES];
    self.mapView.centerCoordinate = initialCoordinate;
    [self.mapView setUserTrackingMode:MKUserTrackingModeFollow animated:YES];
}

- (void)initializeLocationManager {
    // Check to ensure location services are enabled
    if(![CLLocationManager locationServicesEnabled]) {
        [self showAlertWithMessage:@"You need to enable location services to use this app."];
        return;
    }

    _locationManager = [[CLLocationManager alloc] init];
    _locationManager.delegate = self;
}


- (void) initializeRegionMonitoring:(NSArray*)geofences {

    if (_locationManager == nil) {
        [NSException raise:@"Location Manager Not Initialized" format:@"You must initialize location manager first."];
    }

    if(![CLLocationManager regionMonitoringAvailable]) {
        [self showAlertWithMessage:@"This app requires region monitoring features which are unavailable on this device."];
        return;
    }

    for(CLRegion *geofence in geofences) {
        [_locationManager startMonitoringForRegion:geofence];
    }
}

- (NSArray*) buildGeofenceData {
    NSString* plistPath = [[NSBundle mainBundle] pathForResource:@"regions" ofType:@"plist"];
    _regionArray = [NSArray arrayWithContentsOfFile:plistPath];

    NSMutableArray *geofences = [NSMutableArray array];
    for(NSDictionary *regionDict in _regionArray) {
        CLRegion *region = [self mapDictionaryToRegion:regionDict];
        [geofences addObject:region];
    }

    return [NSArray arrayWithArray:geofences];
}

- (CLRegion*)mapDictionaryToRegion:(NSDictionary*)dictionary {
    NSString *title = [dictionary valueForKey:@"title"];

    CLLocationDegrees latitude = [[dictionary valueForKey:@"latitude"] doubleValue];
    CLLocationDegrees longitude =[[dictionary valueForKey:@"longitude"] doubleValue];
    CLLocationCoordinate2D centerCoordinate = CLLocationCoordinate2DMake(latitude, longitude);

    CLLocationDistance regionRadius = [[dictionary valueForKey:@"radius"] doubleValue];

    return [[CLRegion alloc] initCircularRegionWithCenter:centerCoordinate
                                                   radius:regionRadius
                                               identifier:title];
}

- (void)initializeLocationUpdates {
    [_locationManager startUpdatingLocation];
}

#pragma mark - Location Manager - Region Task Methods

- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region {
    NSLog(@"Entered Region - %@", region.identifier);
    [self showRegionAlert:@"Entering Region" forRegion:region.identifier];
}

- (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region {
    NSLog(@"Exited Region - %@", region.identifier);
    [self showRegionAlert:@"Exiting Region" forRegion:region.identifier];
}

- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region {
    NSLog(@"Started monitoring %@ region", region.identifier);
}

#pragma mark - Location Manager - Standard Task Methods

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    self.coordinateLabel.text = [NSString stringWithFormat:@"%f,%f",newLocation.coordinate.latitude, newLocation.coordinate.longitude];
}
#pragma mark - Alert Methods

- (void) showRegionAlert:(NSString *)alertText forRegion:(NSString *)regionIdentifier {
    UIAlertView *message = [[UIAlertView alloc] initWithTitle:alertText
                                                      message:regionIdentifier
                                                     delegate:nil
                                            cancelButtonTitle:@"OK"
                                            otherButtonTitles:nil];
    [message show];
}

- (void)showAlertWithMessage:(NSString*)alertText {
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Location Services Error"
                                                        message:alertText
                                                       delegate:self
                                              cancelButtonTitle:@"Ok"
                                              otherButtonTitles:nil];
    [alertView show];
}

@end

视图控制器.m

#import "ViewController.h"
#import <CoreLocation/CoreLocation.h>


@implementation ViewController

@synthesize coordinateLabel;
@synthesize mapView;
@synthesize kmlParser;

CLLocationManager *_locationManager;
NSArray *_regionArray;

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self initializeMap];
    [self initializeLocationManager];
    NSArray *geofences = [self buildGeofenceData];
    [self initializeRegionMonitoring:geofences];
    [self initializeLocationUpdates];


    // Locate the path to the route.kml file in the application's bundle
    // and parse it with the KMLParser.
    NSString *path = [[NSBundle mainBundle] pathForResource:@"urbanPOIsthlm" ofType:@"kml"];
    NSURL *url = [NSURL fileURLWithPath:path];
    kmlParser = [[KMLParser alloc] initWithURL:url]; 
    [kmlParser parseKML]; 

    // Add all of the MKOverlay objects parsed from the KML file to the map.
    NSArray *overlays = [kmlParser overlays]; 
    [mapView addOverlays:overlays]; 

    // Add all of the MKAnnotation objects parsed from the KML file to the map.
    NSArray *annotations = [kmlParser points];
    [mapView addAnnotations:annotations];

    // Walk the list of overlays and annotations and create a MKMapRect that
    // bounds all of them and store it into flyTo.
    MKMapRect flyTo = MKMapRectNull;
    for (id <MKOverlay> overlay in overlays) {
        if (MKMapRectIsNull(flyTo)) {
            flyTo = [overlay boundingMapRect];
        } else {
            flyTo = MKMapRectUnion(flyTo, [overlay boundingMapRect]);
        }
    }

    for (id <MKAnnotation> annotation in annotations) {
        MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
        MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0);
        if (MKMapRectIsNull(flyTo)) {
            flyTo = pointRect;
        } else {
            flyTo = MKMapRectUnion(flyTo, pointRect);
        }
    }

    // Position the map so that all overlays and annotations are visible on screen.
    mapView.visibleMapRect = flyTo;
}


- (void)viewDidUnload
{
    [self setCoordinateLabel:nil];
    [self setMapView:nil];
    //DERAS alltså KML!!!
    [kmlParser release];
    ///
    [super viewDidUnload];
}

/////Deras alltså KML!!!
#pragma mark MKMapViewDelegate

- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
{
    return [kmlParser viewForOverlay:overlay];
}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
    return [kmlParser viewForAnnotation:annotation];
}
//////////
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

- (void)initializeMap {
    CLLocationCoordinate2D initialCoordinate;
    initialCoordinate.latitude = 59.3353733;
    initialCoordinate.longitude = 18.0712647;

    [self.mapView setRegion:MKCoordinateRegionMakeWithDistance(initialCoordinate, 400, 400) animated:YES];
    self.mapView.centerCoordinate = initialCoordinate;
    [self.mapView setUserTrackingMode:MKUserTrackingModeFollow animated:YES];
}

- (void)initializeLocationManager {
    // Check to ensure location services are enabled
    if(![CLLocationManager locationServicesEnabled]) {
        [self showAlertWithMessage:@"You need to enable location services to use this app."];
        return;
    }

    _locationManager = [[CLLocationManager alloc] init];
    _locationManager.delegate = self;
}


- (void) initializeRegionMonitoring:(NSArray*)geofences {

    if (_locationManager == nil) {
        [NSException raise:@"Location Manager Not Initialized" format:@"You must initialize location manager first."];
    }

    if(![CLLocationManager regionMonitoringAvailable]) {
        [self showAlertWithMessage:@"This app requires region monitoring features which are unavailable on this device."];
        return;
    }

    for(CLRegion *geofence in geofences) {
        [_locationManager startMonitoringForRegion:geofence
                            desiredAccuracy:kCLLocationAccuracyBest];
    }
}

- (NSArray*) buildGeofenceData {
    NSString* plistPath = [[NSBundle mainBundle] pathForResource:@"regions" ofType:@"plist"];
    _regionArray = [NSArray arrayWithContentsOfFile:plistPath];

    NSMutableArray *geofences = [NSMutableArray array];
    for(NSDictionary *regionDict in _regionArray) {
        CLRegion *region = [self mapDictionaryToRegion:regionDict];
        [geofences addObject:region];
    }

    return [NSArray arrayWithArray:geofences];
}

- (CLRegion*)mapDictionaryToRegion:(NSDictionary*)dictionary {
    NSString *title = [dictionary valueForKey:@"title"];    
    CLLocationDegrees latitude = [[dictionary valueForKey:@"latitude"] doubleValue];
    CLLocationDegrees longitude =[[dictionary valueForKey:@"longitude"] doubleValue];
    CLLocationCoordinate2D centerCoordinate = CLLocationCoordinate2DMake(latitude, longitude);
    //CLLocationDistance regionRadius = 50.000;

    CLLocationDistance regionRadius = [[dictionary valueForKey:@"radius"] doubleValue]; //<--STOD DOUBLE ISTÄLLET


    return [[CLRegion alloc] initCircularRegionWithCenter:centerCoordinate
                                                   radius:regionRadius
                                               identifier:title];
}


- (void)initializeLocationUpdates {
    [_locationManager startUpdatingLocation];
}


#pragma mark - Location Manager - Region Task Methods

- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region{
    NSLog(@"Entered Region - %@", region.identifier);
    [self showRegionAlert:@"Entering Region" forRegion:region.identifier];
}

- (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region {
    NSLog(@"Exited Region - %@", region.identifier);
    [self showRegionAlert:@"Exiting Region" forRegion:region.identifier];
}

- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region {
    NSLog(@"Started monitoring %@ region", region.identifier);
}


#pragma mark - Location Manager - Standard Task Methods


- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    self.coordinateLabel.text = [NSString stringWithFormat:@"%f,%f",newLocation.coordinate.latitude, newLocation.coordinate.longitude];
}


#pragma mark - Alert Methods

- (void) showRegionAlert:(NSString *)alertText forRegion:(NSString *)regionIdentifier {
    UIAlertView *message = [[UIAlertView alloc] initWithTitle:alertText
                                                      message:regionIdentifier
                                                     delegate:nil
                                            cancelButtonTitle:@"OK"
                                            otherButtonTitles:nil];
    [message show];
}

- (void)showAlertWithMessage:(NSString*)alertText {
    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Location Services Error"
                                                        message:alertText
                                                       delegate:self
                                              cancelButtonTitle:@"Ok"
                                              otherButtonTitles:nil];
    [alertView show];
}

@end

Appdelegate.h

#import <UIKit/UIKit.h>

@class ViewController;


@interface AppDelegate : NSObject <UIApplicationDelegate> {
    UIWindow *window;
    ViewController *viewController;
}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet ViewController *viewController;


@end

Appdelegate.m

#import "AppDelegate.h"

#import "ViewController.h"

@implementation AppDelegate

//DERAS ALLTSÅ KML!!
@synthesize window;
@synthesize viewController;
//

//Deras alltså KML!!
#pragma mark -
#pragma mark Application lifecycle
//

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];

    //Deras alltså KML!!
    [window addSubview:viewController.view];
    //
    return YES;
}

//Deras alltså KML!!!
- (void)dealloc {
    [viewController release];
    [window release];
    [super dealloc];
}
//

@end