[英]Objective-C | Take properties and protocols declared and implemented from .m and expose publicly in .h interface
[英]Clarification needed about the rules of properties declared in protocols
我對協議中聲明的屬性有一些疑問。
返回類型差異
@protocol IHaveProperties
@required
@property (nonatomic, strong) IAmOfTypeX *propertyOfProtocolType;
@property (nonatomic, strong) NSArray *array;
@end
@interface ClassThatHasProperties : NSObject<IHaveProperties>
@property (nonatomic, strong) ImplementationOfTypeX *propertyOfProtocolType;
@property (nonatomic, strong) NSMutableArray *array;
@end
好的,所以我嘗試使用協議/類組合進行此操作,但令我沮喪的是,它進行了編譯。
這是如何運作的? 從技術上講,這不符合接口嗎?
屬性聲明修飾符
@protocol IHaveProperty
@required
@property (nonatomic, strong, readonly) *example;
@end
@interface HaveProperty : NSObject<IHaveProperty>
@property (nonatomic, strong, readonly) *example;
@end
我的Mac現在正在重新啟動,因此我無法嘗試該操作,但我認為這可以,因為協議聲明沒有任何支持。 所有的修飾符都不會對調用者感興趣,而只會對實現該協議的類感興趣。
如果查看<NSObject>
協議 ,您會發現它將方法和屬性結合在一起:
@protocol NSObject
- (BOOL)isEqual:(id)object; @property (readonly) NSUInteger hash;
@property (readonly) Class superclass;
- (Class)class OBJC_SWIFT_UNAVAILABLE("use 'anObject.dynamicType' instead");
- (instancetype)self;
- (id)performSelector:(SEL)aSelector;
- (id)performSelector:(SEL)aSelector withObject:(id)object;
- (id)performSelector:(SEL)aSelector withObject:(id)object1 withObject:(id)object2;
- (BOOL)isProxy;
- (BOOL)isKindOfClass:(Class)aClass;
- (BOOL)isMemberOfClass:(Class)aClass;
- (BOOL)conformsToProtocol:(Protocol *)aProtocol;
- (BOOL)respondsToSelector:(SEL)aSelector;
- (instancetype)retain OBJC_ARC_UNAVAILABLE;
- (oneway void)release OBJC_ARC_UNAVAILABLE;
- (instancetype)autorelease OBJC_ARC_UNAVAILABLE;
- (NSUInteger)retainCount OBJC_ARC_UNAVAILABLE;
- (struct _NSZone *)zone OBJC_ARC_UNAVAILABLE;
@property (readonly, copy) NSString *description; @optional @property
(readonly, copy) NSString *debugDescription;
@end
您必須使用了description
或superclass
屬性。 與函數相比,屬性的處理方式沒有任何區別。 實現協議的類將提供協議屬性的獲取器和/或設置器。 同樣,擁有委托對象的類將調用其屬性,例如: self.delegate.propertyName.
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