capturing self strongly in this block is likely to lead to a retain cycle，capturingretain

capturing self strongly in this block is likely to lead to a retain cycle，capturingretain

一個使用Block文法的執行個體變數，在引用另一個執行個體變數的時候，經常會引起retain cycle。

capturing self strongly in this block is likely to lead to a retain cycle

_items = [[NSMutableArray alloc] init];      _block = ^{          [_items addObject:@"Hello!"]; //_block引用了_items，導致retain cycle。      }; 

寫成下面格式

__block ViewController *blockSelf = self;  _block = ^{      [blockSelf->_items addObject:@"Hello!"];  };

Capturing self strongly in this block is likely to lead to retain cycle

block 是代碼塊的意思。
甲裡引用乙，乙裡引用甲，就會導致 “retain cycle” -- “形成怪圈”的錯誤。
網上資料：
解決的辦法是 建立一個本地變數 指向 自己(self).
例如：_items 實際上是 self->items,
_block 對象在建立的時候會被retain一次
改成：
__block ViewController *blockSelf = self;
_block = ^{
[blockSelf->_items addObject:@"Hello!"];
};
就可以了。
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DoSomethingManager *manager = [[DoSomethingManager alloc] init];

manager.complete = ^{

//...complete actions

[manager otherAction];

manager.complete = nil; // Objective-C 用這種方法破壞怪圈。

[manager release];

};
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報一個異常，問怎可以消除

解析出了問題，是木馬程式