iOS-关联属性Associate

标签：associate   runtime   

iOS分类用的比较多，基本都是扩展方法，如果想要扩展属性，就要用到runtime了，使用

objc_getAssociatedObject

objc_setAssociatedObject

上代码：给Test新建一个分类，关联一个属性name;

#import "Test.h"

#import "Property.h"

@interface Test (pp)

@property(nonatomic , strong) Property* name;

@end

#import "Test+pp.h"

#import <objc/runtime.h>

static char* NAME;

@implementation Test (pp)

- (Property *)name{

   return  objc_getAssociatedObject(self, NAME);

}

- (void)setName:(Property *)name{

    objc_setAssociatedObject(self, NAME, name, OBJC_ASSOCIATION_COPY_NONATOMIC);

}

@end

注意因为用的是copy，所以Property类要遵守NSCopying协议。

在外部使用：

Property* two = [Property new];

test.name = two;

内存释放会不会有问题？

#import "Property.h"

@implementation Property

-(void)dealloc{

    NSLog(@"%s",__FUNCTION__);

}

- (id)copyWithZone:(NSZone *)zone{

    Property* pro  = [Property allocWithZone:zone];

    return pro;

}

@end

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    self.array = [NSMutableArray array];

    Property* pro = [[Property alloc] init];

    Test* test = [Test new];

    test.name = pro;

    Property* two = [Property new];

    test.name = two;

    [self.array addObject:pro];

    [self.array addObject:two];

    return YES;

}

输入打印结果：

2015-02-27 23:43:51.816 PNChartDemo[1486:40966] -[Property dealloc]

2015-02-27 23:43:51.816 PNChartDemo[1486:40966] -[Property dealloc]

iOS-关联属性Associate

标签：associate   runtime   

原文地址：http://blog.csdn.net/growinggiant/article/details/43975199