Question

我有一些typedef：

typedef void (^myBlock)(SomeObject);

我有一些对象

@interface SomeObject : NSObject
@end

// Method of some arbitrary class
- (void) someMethod1 {
    SomeObject *someObject = [[SomeObject alloc] init];

    myBlock block = ^(SomeObject obj){
        // When _block(someObject)_ will be called inside someQueue - 
        // Is it guaranteed that someObject will be alive, retained inside me?       

        // Do something complex and involving (or not) obj ...    
    }

    dispatch_async(someQueue, ^{
        // Some bunch of code - after which we are sure that 
        // by the next line someMethod1 will run out, so its scope is lost

        block(someObject);
    });
}

问题放在块变量的块中：是否保证我们传递给 someQueue 队列内的块块的someObject对象将活着并保留在块块中？

这个问题是我刚问过的问题的一个更复杂的变化：Does a passing of an object to a block guarantee that its lifecycle will be retained?。

Answer 1

该块以及它将使用的所有内容将一直保留到块执行之后.. 已捕获

Answer 2

我相信你提出的问题与上一个问题相同。这里唯一的区别是你没有在区块内调用方法，而是在调用一个区块。
也许我的答案还不够明确：一切都保留在一个区块内，即使是一个区块也是如此。

dispatch_async(someQueue, ^{
    // Some bunch of code - after which we are sure that 
    // by the next line someMethod1 will run out, so its scope is lost

    block(someObject);
});

在块内部，您调用someObject，因此捕获someObject。此外，块也被捕获。

调用带变量的块是否保证其生命周期将被保留？

2 个答案: