在块中调用另一个引用self的方法的方法是否会导致保留周期？

Question

Can doFirst cause a retain cycle here?

@interface Example : NSObject
@property (nonatomic, strong) void (^block)();
@end

@implementation Example

- (void)doFirst
{
    __weak id weakSelf = self;
    self.block = ^ {            
        [weakSelf doSecond];
    };

    self.block();
}

- (void)doSecond
{
    self.value = //...
    // do other stuff involving self
}
@end

Answer 1

Unlike blocks, methods are not objects; they cannot hold a permanent reference to objects.

Your code would not cause a retain cycle. The fact that the code inside doSecond references self explicitly does not mean that self would get retained an extra time. When your block calls doSecond , its self comes from the weakSelf reference inside doFirst .

Note: When you store blocks as properties, use (nonatomic, copy) instead of (nonatomic, strong) .

Answer 2

No It won't. Because It just point to method which won't hold whatwhere inside methods which just an reference as like object.