CLLocationManager

Requesting Authorization for Location Services

- (void)requestWhenInUseAuthorization
- (void)requestAlwaysAuthorization

Determining the Availability of Services 

+ (CLAuthorizationStatus)authorizationStatus
+ (BOOL)locationServicesEnabled
+ (BOOL)deferredLocationUpdatesAvailable
+ (BOOL)significantLocationChangeMonitoringAvailable
+ (BOOL)headingAvailable
+ (BOOL)isMonitoringAvailableForClass:(Class)regionClass
+ (BOOL)isRangingAvailable

配置状态CLAuthorizationStatus：

typedef enum {
   kCLAuthorizationStatusNotDetermined  = 0,//未设置
   kCLAuthorizationStatusRestricted ,//不允许使用而且不可设置。例如家长控制等
   kCLAuthorizationStatusDenied ,//不允许使用
   kCLAuthorizationStatusAuthorized ,//可以使用。IOS8反对使用。
   kCLAuthorizationStatusAuthorizedAlways  = kCLAuthorizationStatusAuthorized ,//IOS8新增
   kCLAuthorizationStatusAuthorizedWhenInUse //IOS8新增
} CLAuthorizationStatus;