Objective-C - 测试被释放/释放的对象实例 [英] Objective-C - Test for object instance being dealloced/freed

问题描述

有一些方法来测试一个目标c实例被释放/释放（retain count == 0）

There's some way to test for an objective-c instance for being dealloced/freed (retain count == 0)??

例如，对象A有一个引用（指针）到对象B，但是对象B可以在内存低级别释放，我如何测试引用B以确保它被释放??

By example, object A have a reference (pointer) to object B, but object B can be freed in memory low levels, how i test reference B to be sure it was dealloced??

@interface A : NSObject {
    B b;
}

@implementation A {

- (void) someAction:(id) sender {
    //is b previously dealloced?? 
    if ..... ???? {
        b = [[B alloc] init];
    }
    // continue
}
}

谢谢！

推荐答案

你不能测试一个对象是否已经被释放，再谈。如果你在发布时将 b 设置为nil（例如，通过执行 self.b = nil 你可以测试nil然后创建对象。

You can't test whether an object has been dealloced since, obviously, the object isn't there to talk to anymore. If you set b to nil when you release it (say, by doing self.b = nil), though, you can test for nil and create the object then.

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