ios - iOS8 CLLocationManager在后台状态返回Null

在iOS8中，当我将我的应用放回地面时，CLLocationManager在位置返回Null，我也无法在后台模式下更新位置，也无法进行requestAlwaysAuthorization

    CLLocationManager *lm = [[CLLocationManager alloc] init];
    lm.delegate = self;
    lm.desiredAccuracy = kCLLocationAccuracyBest;
    lm.distanceFilter = kCLDistanceFilterNone;
    [lm requestAlwaysAuthorization];
    [lm startUpdatingLocation];

最佳答案

请找到以下代码以在后台模式下获取位置-

请在plist文件中输入NSLocationAlwaysUsageDescription的文本。

请从项目设置中选择背景模式下的位置更新-

AppDelegate.h

//
//  AppDelegate.h
//  LocationTest
//
//  Created by Santu C on 28/05/15.
//  Copyright (c) 2015 company. All rights reserved.
//

#import <UIKit/UIKit.h>
#import<CoreLocation/CoreLocation.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;


@property(strong,nonatomic) CLLocationManager *locationManager;


@end

AppDelegate.m

//
//  AppDelegate.m
//  LocationTest
//
//  Created by Santu C on 28/05/15.
//  Copyright (c) 2015 company. All rights reserved.
//

#import "AppDelegate.h"

@implementation AppDelegate
@synthesize locationManager;

#define CONST_TIME_INTERVAL 60.0

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

    [self location];



    // Override point for customization after application launch.
    return YES;
}



-(void)location
{


    NSLog(@"location called");

    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.delegate = self;
    self.locationManager.distanceFilter = kCLDistanceFilterNone;
    self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
    self.locationManager.pausesLocationUpdatesAutomatically = NO;

#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 80000

    if ([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)])
    {
        [self.locationManager requestAlwaysAuthorization];
    }
#endif

    [self.locationManager startUpdatingLocation];

}


- (void)startUpdatingLocation
{
    NSLog(@"startUpdatingLocation called");

    self.locationManager.delegate = self;
    [self.locationManager startUpdatingLocation];
}

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{


    NSLog(@"locationManager didUpdateLocations");

    CLLocation *newLocation = (CLLocation *)[locations lastObject];


    NSLog(@"dLongitude : %f", newLocation.coordinate.latitude);
    NSLog(@"dLatitude : %f", newLocation.coordinate.longitude);



}




- (void)applicationDidEnterBackground:(UIApplication *)application
{
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.

     [self startUpdatingLocation];
}



@end

希望这个能对您有所帮助

关于ios - iOS8 CLLocationManager在后台状态返回Null，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/30483700/