CATransaction 属性和方法
+ (void)begin;
+ (void)commit;
+ (void)flush;
+ (void)lock;
+ (void)unlock;
+ (CFTimeInterval)animationDuration;
+ (void)setAnimationDuration:(CFTimeInterval)dur;
+ (nullable CAMediaTimingFunction *)animationTimingFunction;
+ (void)setAnimationTimingFunction:(nullable CAMediaTimingFunction *)function;
+ (BOOL)disableActions;
+ (void)setDisableActions:(BOOL)flag;
+ (nullable void (^)(void))completionBlock;
+ (void)setCompletionBlock:(nullable void (^)(void))block;
+ (nullable id)valueForKey:(NSString *)key;
+ (void)setValue:(nullable id)anObject forKey:(NSString *)key;
/** Transaction property ids. **/
CA_EXTERN NSString * const kCATransactionAnimationDuration
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);
CA_EXTERN NSString * const kCATransactionDisableActions
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);
CA_EXTERN NSString * const kCATransactionAnimationTimingFunction
CA_AVAILABLE_STARTING (10.6, 3.0, 9.0, 2.0);
CA_EXTERN NSString * const kCATransactionCompletionBlock
CA_AVAILABLE_STARTING (10.6, 4.0, 9.0, 2.0);
