iphone - 使用 objective-c 中的 block 声明 iVar

Question

我是 block 新手。我想创建一个 iVar NSMutableArray，我可以在 block 方法中访问它。有人可以告诉我如何使用 _block 关键字声明它吗？`

@interface ViewController : UIViewController
{
    __block NSMutableArray *array;
}
@property (nonatomic, weak) NSMutableArray *array;

Answer 1

您不需要在 iVar 前面设置 __block。

根据:http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/Blocks/Articles/bxVariables.html

When a block is copied, it creates strong references to object variables used within the block. If you use a block within the implementation of a method:

• If you access an instance variable by reference, a strong reference is made to self;
• If you access an instance variable by value, a strong reference is made to the variable.