1.导入系统框架

import <CoreLocation/CoreLocation.h>

实现CLLocationManagerDelegate协议
声明位置管理对象属性
@property (nonatomic, strong) CLLocationManager *locationManager;
2.初始化CLLocationManager对象获取位置信息

-(void)initLocation
{
    _locationManager = [[CLLocationManager alloc] init];
    _locationManager.delegate = self;
    // 设置定位精度
    [_locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
    // 请求用户权限：
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8) {
       // 只在前台开启定位
        [_locationManager requestWhenInUseAuthorization];
                 // 在后台也可定位
        //        [_locationManager requestAlwaysAuthorization];
    }
    //    更新用户位置
    [_locationManager startUpdatingLocation];
}

3.定位权限变化通知

-(void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status
{
    switch (status) {
        case kCLAuthorizationStatusNotDetermined:
        {
            if ([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) {
                [self.locationManager requestAlwaysAuthorization];
            }
            NSLog(@"用户还未决定授权");
            break;
        }
        case kCLAuthorizationStatusRestricted:
        {
            NSLog(@"访问受限");
            // 通过 ip 获取位置信息
            break;
        }
        case kCLAuthorizationStatusDenied:
        {
            // 类方法，判断是否开启定位服务
            if ([CLLocationManager locationServicesEnabled]) {
                NSLog(@"定位服务开启，被拒绝");
                
            } else {
                NSLog(@"定位服务关闭，不可用");
            }
            break;
        }
        case kCLAuthorizationStatusAuthorizedAlways:
        {
//            NSLog(@"获得前后台授权");
            break;
        }
        case kCLAuthorizationStatusAuthorizedWhenInUse:
        {
//            NSLog(@"获得前台授权");
            break;
        }
        default:
            break;
    }
}

4.用户位置信息变化回调

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations  {
    if (locations && [locations count] > 0) {
        CLLocation *newLocation = locations[0];
        //CLLocationCoordinate2D oldCoordinate = newLocation.coordinate;
        [manager stopUpdatingLocation];
        CLGeocoder *geocoder = [[CLGeocoder alloc]init];
        [geocoder reverseGeocodeLocation:newLocation completionHandler:^(NSArray<CLPlacemark *> * _Nullable placemarks, NSError * _Nullable error) {
            if (placemarks && [placemarks count] > 0) {
                // 纬度
                CLLocationDegrees latitude = newLocation.coordinate.latitude;
                // 经度
                CLLocationDegrees longitude = newLocation.coordinate.longitude;
                NSString *cityName = @"火星";
                for (CLPlacemark *place in placemarks) {
                    if (place.locality.length > 0) {
                        cityName = place.locality;
                    }
                }
            }
        }];
    }
}

5.如果用户拒绝访问位置信息，这时可以通过访问淘宝 ip 获取ip地址信息
http://ip.taobao.com/service/getIpInfo.php?ip=myip