1.选中target-->Gapability，打开Background Modes模式，并勾选Location updates

2.代码如下：

ViewController.h
<pre>#import <UIKit/UIKit.h>

import <CoreLocation/CoreLocation.h>

@interface ViewController : UIViewController<CLLocationManagerDelegate>

//定位管理对象
@property(nonatomic,strong)CLLocationManager *manager;

@end</pre>
ViewController.m
<pre>#import "ViewController.h"

@interface ViewController ()
{
CLGeocoder *_coder;
//存储上一次的位置
}
@end

@implementation ViewController

• (void)viewDidLoad
  {
  [super viewDidLoad];
  self.view.backgroundColor=[UIColor whiteColor];
  //1.创建定位管理对象
  _manager=[[CLLocationManager alloc]init];
  _coder=[[CLGeocoder alloc]init];
  //2.设置属性 distanceFilter、desiredAccuracy
  _manager.distanceFilter=kCLDistanceFilterNone;//实时更新定位位置
  _manager.desiredAccuracy=kCLLocationAccuracyBest;//定位精确度

  if([_manager respondsToSelector:@selector(requestAlwaysAuthorization)])
  {
  [_manager requestAlwaysAuthorization];
  }
  //该模式是抵抗程序在后台被杀，申明不能够被暂停
  _manager.pausesLocationUpdatesAutomatically=NO;
  //3.设置代理
  _manager.delegate=self;
  //4.开始定位
  [_manager startUpdatingLocation];
  //5.获取朝向
  [_manager startUpdatingHeading];

}

pragma mark-CLLocationManager代理方法

//定位失败时调用的方法
-(void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
NSLog(@"%@",error);
}
//定位成功调用的的方法
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
if(locations.count>0)
{
// 获取位置信息
CLLocation *loc=[locations lastObject];
// 获取经纬度的结构体
CLLocationCoordinate2D coor=loc.coordinate;

    CLLocation *location=[[CLLocation alloc]initWithLatitude:coor.latitude longitude:coor.longitude];
    
    [_coder reverseGeocodeLocation:location completionHandler:^(NSArray *placemarks, NSError *error) {
        CLPlacemark *pmark=[placemarks firstObject];
        NSLog(@"%@",pmark.addressDictionary);
        NSString *city=pmark.addressDictionary[@"City"];
        if([city hasSuffix:@"市辖区"])
            city=[city substringToIndex:city.length-3];
        if([city hasSuffix:@"市"])
            city=[city substringToIndex:city.length-1];
        NSLog(@"%@",city);
    }];
}

}
@end</pre>
Appdelegate.m
<pre>#import "AppDelegate.h"

import <CoreLocation/CoreLocation.h>

import "ViewController.h"

@interface AppDelegate ()

@end

@implementation AppDelegate

• (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  self.window.rootViewController=[ViewController new];
  return YES;
  }

• (void)applicationDidEnterBackground:(UIApplication )application {
  if([CLLocationManager significantLocationChangeMonitoringAvailable])
  {
  ViewControllervc=(ViewController *)self.window.rootViewController;
  [vc.manager stopUpdatingLocation];
  [vc.manager startMonitoringSignificantLocationChanges];
  }
  else
  {
  NSLog(@"significant Location Change not Available");
  }
  }

• (void)applicationDidBecomeActive:(UIApplication )application {
  if([CLLocationManager significantLocationChangeMonitoringAvailable])
  {
  ViewControllervc=(ViewController *)self.window.rootViewController;
  [vc.manager stopMonitoringSignificantLocationChanges];
  [vc.manager startUpdatingLocation];
  }
  else
  {
  NSLog(@"significant Location Change not Available");
  }
  }

@end</pre>