block 中的循环引用问题

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https://gist.github.com/SeanChense/b4dfb7db4e983e88e963

这样调用的话会引起 self 的循环引用吗？

for app users

调用

引用

block

6 replies • 2015-08-07 14:04:46 +08:00

tane05

Aug 6, 2015 via iPhone

不会，block捕获的是它作用域的变量.

CDuXZMAPgHp1q9ew

Aug 6, 2015

加了weakself肯定不会
但是用self 也可能不会引起循环引用, 和 `foo handle:^{}` 的实现有关

pengjay

Aug 6, 2015

不会

SeanChense

Aug 6, 2015 via iPhone

@wujichao 怎么讲？

SeanChense

Aug 6, 2015 via iPhone

@tane05
@pengjay

谢谢

banxi1988

Aug 7, 2015

一般比较更好一写法是：

```objc
[foo handler: ^{
id strongself = weakself;
if(strongself){
[strongself doSomething]; // 直接用 weakself 有可能 crash,因为其可能变成了野指针
}
}];
```