定位

如果在一个App的某个部分需要用到定位功能，比如查看附近的某些信息,那么需要用到CLLocationManager这个类
导入#import <CoreLocation/CoreLocation.h>

首先创建locationManager对象

@property (nonatomic, strong) CLLocationManager *locationManager;

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [self requestLocation];
}

// 重写Getter方法
-(CLLocationManager *)locationManager{
    if (!_locationManager) {
        _locationManager = [[CLLocationManager alloc] init];
        // 设置精度
        _locationManager.desiredAccuracy = kCLLocationAccuracyBest;
        // 100米内不需要重新定位
        _locationManager.distanceFilter = 100;
        // 绑定委托
        _locationManager.delegate = self;
    }
    return _locationManager;
}

// 请求定位
- (void) requestLocation{
    // 请求用户权限 开启定位
    // 判断当前App是否开启定位服务
    CLAuthorizationStatus status = [CLLocationManager authorizationStatus];
    // 判断是否已授权
    if (status == kCLAuthorizationStatusNotDetermined) {
        // 请求授权
        [self.locationManager requestWhenInUseAuthorization];
    }
    // 如果关闭定位服务 弹框提示
    else if (status == kCLAuthorizationStatusDenied){
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"提示" message:@"定位服务已关闭,请在设置中找到该应用,然后开启定位服务" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil];
        [alertView show];
    }
    else{
        [self.locationManager startUpdatingLocation];
    }
}

#pragma mark - CLLocationDelegate
// 授权状态改变时回调
- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status{
    if (status == kCLAuthorizationStatusDenied) {
        NSLog(@"不允许");
    }
    else{
        // 启动定位服务
        [manager startUpdatingLocation];
    }
}

- (void)locationManager:(CLLocationManager *)manager
     didUpdateLocations:(NSArray *)locations {
    // 先判断有没有位置信息
    if (locations.count > 0) {
        // 停止定位
        [manager stopUpdatingLocation];
        // 从数组中取出任意一个位置信息
        CLLocation *location = [locations firstObject];
        // 传入位置信息 调用数据请求方法
        [self requestNearApp:location.coordinate];
    }
}

nearApp.png