在ios中实现CLLocationManager的didUpdateLocations委托方法

Question

我已经在 DashboardController.m 中实现了 -(void)localnotification。现在我想访问 localnotification 并将 didUpdateLocations 委托方法实现到 settingsController.m 类中。到目前为止，我的方法是：

DashBoardViewController.h

#import <CoreLocation/CoreLocation.h>

@class AppDelegate;
@interface DashBoardViewController : UIViewController<CLLocationManagerDelegate, UIAlertViewDelegate>{

    AppDelegate *appDel;
}
@property(nonatomic,strong) CLLocationManager *locationManager;
@property (nonatomic,retain) CLLocation *current;

-(void)localnotification;
@end

DashBoardViewController.m

#import "DashBoardViewController.h"
#import "AppDelegate.h"

@interface DashBoardViewController ()
@end 
@implementation DashBoardViewController

@synthesize current,locationManager;
- (void)viewDidLoad
{
    [super viewDidLoad];
    appDel = (AppDelegate*)[UIApplication sharedApplication].delegate;
    [self localnotification];
}

-(void)localnotification{ 
    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    locationManager.distanceFilter = kCLDistanceFilterNone;
    locationManager.desiredAccuracy = kCLLocationAccuracyBest;

    [locationManager startMonitoringSignificantLocationChanges];
}

现在在 SettingController.m 我这样访问：

@implementation SettingsViewController
DashBoardViewController *dash;

- (void)viewDidLoad {
    [super viewDidLoad];
    appDel = (AppDelegate*)[UIApplication sharedApplication].delegate;
    dash=[[DashBoardViewController alloc] init];
    [dash localnotification];
    NSArray *locations;
    [self locationManager:appDel.locationManager didUpdateLocations:locations];
}


- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    //location 1
    CLLocation *locA = [[CLLocation alloc] initWithLatitude:appDel.latVal longitude:appDel.longVal];

    //location 2
    CLLocation *locB = [[CLLocation alloc] initWithLatitude:appDel.locationManager.location.coordinate.latitude longitude:appDel.locationManager.location.coordinate.longitude ];

    appDel.latVal = appDel.locationManager.location.coordinate.latitude; //Latitute of the location
    appDel.longVal = appDel.locationManager.location.coordinate.longitude; //Longitude of the location

    //Difference between location 1 & location 2
    CLLocationDistance dist = [locA distanceFromLocation:locB];
    NSLog(@"Difference from Settings: %ld",lroundf(dist));
    NSLog(@"Last Location's Object Settings: %@",[locations lastObject]);
}

但是 [locations lastObject] 在 settingsController 类中返回 null。在视图控制器类中，我不必定义 locations 数组，但在设置类中，因为我只访问 localnotification 方法，我已经声明了位置数组，否则会出错。我应该通过什么

[self locationManager:appDel.locationManager didUpdateLocations:?];

Answer 1

这是在多个视图控制器中使用位置管理器的最佳方式：

在 AppDelegate.h

中

@interface AppDelegate : UIResponder <UIApplicationDelegate, CLLocationManagerDelegate>
@property (strong, nonatomic) UIWindow *window;
@property (nonatomic, strong) CLLocationManager * locationManager;
@property (nonatomic, strong) CLLocation *currentLocation;

在 AppDelegate.m

中

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    if([CLLocationManager locationServicesEnabled]){
        currentLocation_ = [[CLLocation alloc] init];
        locationManager = [[CLLocationManager alloc] init];
        locationManager.delegate = self;
        [locationManager startUpdatingLocation];
    }
}

-(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{
    currentLocation_ = newLocation;
}

现在在 DashBoardViewController 和 SettingsViewController 中

@property (strong, nonatomic) CLLocation *currentLocation;

- (void)viewDidLoad{
    [super viewDidLoad];
    if([CLLocationManager locationServicesEnabled]){
        AppDelegate *appDelegate = (AppDelegate *) [[UIApplication sharedApplication] delegate];
        currentLocation_ = [[CLLocation alloc] initWithLatitude:appDelegate.currentLocation.coordinate.latitude longitude:appDelegate.currentLocation.coordinate.longitude];
    }
}

注意： 以它为例，您可以根据需要对其进行改进。

希望它对你有用。