定制dealloc和ARC（Objective-C） [英] Custom dealloc and ARC (Objective-C)

问题描述

在我的小iPad应用程序中，我有一个使用观察者的切换语言功能。每个视图控制器在其 viewDidLoad：期间向我的观察者注册。

In my little iPad app I have a "switch language" function that uses an observer. Every view controller registers itself with my observer during its viewDidLoad:.

- (void)viewDidLoad
{
    [super viewDidLoad];
    [observer registerObject:self];
}

当用户点击更改语言按钮时，将存储新语言在我的模型中，观察者会收到通知并在其注册对象上调用 updateUi：选择器。

When the user hits the "change language" button, the new language is stored in my model and the observer is notified and calls an updateUi: selector on its registered objects.

这非常有用好吧，除了我在TabBarController中有视图控制器。这是因为当标签栏加载时，它会从其子控件中获取选项卡图标而不初始化视图，因此不会调用 viewDidLoad：，因此这些视图控制器不会收到语言变更通知。因此，我将 registerObject：调用移动到 init 方法。

This works very well, except for when I have view controllers in a TabBarController. This is because when the tab bar loads, it fetches the tab icons from its child controllers without initializing the views, so viewDidLoad: isn't called, so those view controllers don't receive language change notifications. Because of this, I moved my registerObject: calls into the init method.

当我使用 viewDidLoad：向我的观察者注册时，我使用 viewDidUnload：取消注册。由于我现在在 init 中注册，因此在 dealloc 中取消注册是很有意义的。

Back when I used viewDidLoad: to register with my observer, I used viewDidUnload: to unregister. Since I'm now registering in init, it makes a lot of sense to unregister in dealloc.

但这是我的问题。我写的时候：

But here is my problem. When I write:

- (void) dealloc
{
    [observer unregisterObject:self];
    [super dealloc];
}

我收到此错误：

ARC禁止'dealloc'显式消息发送

ARC forbids explicit message send of 'dealloc'

因为我需要调用 [super dealloc] 以确保超级正常清理，但ARC禁止这样做，我现在卡住了。还有另一种方法可以在我的物体死亡时获得通知吗？

Since I need to call [super dealloc] to ensure superclasses clean up properly, but ARC forbids that, I'm now stuck. Is there another way to get informed when my object is dying?

推荐答案

使用ARC时，你根本就不打电话给 [super dealloc] 显式 - 编译器为你处理它（如 Clang LLVM ARC文档，第7.1.2章）：

When using ARC, you simply do not call [super dealloc] explicitly - the compiler handles it for you (as described in the Clang LLVM ARC document, chapter 7.1.2):

- (void) dealloc
{
    [observer unregisterObject:self];
    // [super dealloc]; //(provided by the compiler)
}

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