swift - 如何在 block 外快速创建一个指向自身的弱指针

Question

我想在 swift 中创建一个指向自身的弱指针，就像我们过去在 objective-c 中那样

 __weak Something *weakself = self;

我发现有人在解释如何在 block 中使用“弱 self ”，

    { in [unowned self] ...}

但我不想在我的 block 内定义“weakself”，我想在 block 外定义 weakself

Answer 1

只需使用 weak 关键字定义一个弱引用:

weak var weakSelf = self

来自documentation :

You indicate a weak reference by placing the weak keyword before a property or variable declaration.
...
NOTE: Weak references must be declared as variables, to indicate that their value can change at runtime. A weak reference cannot be declared as a constant.