为分类添加属性

#import <objc/runtime.h>

1.先添加属性，但是不会动态生成带下划线的属性

@property (nonatomic, assign) NSInteger index;

@property (nonatomic, copy) NSString *loginPwd;

@property (nonatomic , copy) void (^indexBlock)(NSInteger index);

2.

1>.如果是基本数据类型

static char strKey = 'm';

- (NSInteger)index{

    return [objc_getAssociatedObject(self, &strKey) intValue];

}

 

- (void)setIndex:(NSInteger)index{

    return objc_setAssociatedObject(self, &strKey, @(index), OBJC_ASSOCIATION_ASSIGN);

}

2>.如果是字符串，自定义对象

static void *str = &str;

-(void)setLoginPwd:(NSString *)loginPwd{

    return objc_setAssociatedObject(self, & str, loginPwd, OBJC_ASSOCIATION_COPY);

}

- (NSString *)loginPwd{

    return objc_getAssociatedObject(self, & str);

}

3>.如果是block类型，类似于字符串类型

static void *strKey3 = &strKey3;

 

-(void)setIndexBlock:(void (^)(NSInteger))indexBlock{

    return objc_setAssociatedObject(self, & strKey3, indexBlock, OBJC_ASSOCIATION_COPY);

 

}

-(void (^)(NSInteger))indexBlock{

    return objc_getAssociatedObject(self, & strKey3);

 }