CLHeading

typedef double CLHeadingComponentValue;

//没有最小的位置更新，也就是不断地更新

extern const CLLocationDegrees kCLHeadingFilterNone;

// 0.0 - 359.9 degrees, 0 表示北方

@property(readonly, nonatomic) CLLocationDirection magneticHeading;

// 0.0 - 359.9 degrees, 0 being true North,位置的指北方向

@property(readonly, nonatomic) CLLocationDirection trueHeading;

//方向的精确度，负数为无效的

@property(readonly, nonatomic) CLLocationDirection headingAccuracy;

//方向上的三维中的三个要素

@property(readonly, nonatomic) CLHeadingComponentValue x;

@property(readonly, nonatomic) CLHeadingComponentValue y;

@property(readonly, nonatomic) CLHeadingComponentValue z;

//时间

@property(readonly, nonatomic, copy) NSDate *timestamp;

//表示方向的字符串

@property (nonatomic, readonly, copy) NSString *description;