Question

子类扩展父类委托，子类工作，但有警告!!!

父类：

@protocol ObjADelegate;

@interface ObjA : NSObject

@property (nonatomic, assign) id<ObjADelegate> delegate;

- (void)doSth1;

@end

@protocol ObjADelegate <NSObject>

- (void)seeA;

@end

子类：

#import "ObjA.h"

@protocol ObjBDelegate;

@interface ObjB : ObjA

@property (nonatomic, assign) id<ObjBDelegate,ObjADelegate> delegate;

- (void)dosth2;

@end

@protocol ObjBDelegate <ObjADelegate>

- (void)seeB;

@end

它有效，但对班级objB的代表发出警告：auto property synthesis will not synthesize property 'delegate';it will be implemented by its superclass , use @dynamic to acknowledge intention

如何删除此警告?????

Answer 1

提示位于警告消息中。您需要在实现中使用@dynamic来告诉编译器属性setter和getter是在别处处理的（在本例中是超类）。

@implementation ObjB

@dynamic delegate;

- (void)dosth2 
{

}

@end

Answer 2

父类：.h

#import <Foundation/Foundation.h>
@protocol ClassADelegate;
@interface ClassA : NSObject{
    id _delegate;
}
@property (nonatomic, assign) id<ClassADelegate> delegate;
- (void)fun1;
@end
@protocol ClassADelegate <NSObject>
- (void)hello;
@end

父类：.m

#import "ClassA.h"
@implementation ClassA
@dynamic delegate;
- (void)fun1{
    if (self.delegate && [self.delegate respondsToSelector:@selector(hello)]) {
        [self.delegate hello];
    }
}
- (void)setDelegate:(id<ClassADelegate>)delegate{
    _delegate = delegate;
}
- (id<ClassADelegate>)delegate{
    return _delegate;
}
@end

子类：.H

#import "ClassA.h"
@protocol ClassBDelegate <NSObject, ClassADelegate>
-(void)nihao;
@end
@interface ClassB : ClassA
@property (nonatomic, assign) id<ClassBDelegate> delegate;
- (void)fun2;
@end

子类：.M

#import "ClassB.h"
@implementation ClassB
@dynamic delegate;
- (void)fun2{
    if (_delegate && [_delegate respondsToSelector:@selector(nihao)]) {
        [_delegate nihao];
    }
}
- (void)setDelegate:(id<ClassBDelegate>)delegate{
    _delegate = delegate;
}
- (id<ClassBDelegate>)delegate{
    return _delegate;
}
@end

子类委托语句必须在标题

上

如何扩展父类委托的子类？

2 个答案: