自定义 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自己.
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,新语言会存储在我的模型中,观察者会收到通知并在其注册的对象上调用 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.
这很有效,除非我在 TabBarController 中有视图控制器.这是因为当标签栏加载时,它从它的子控制器获取标签图标而不初始化视图,所以 viewDidLoad:
没有被调用,所以那些视图控制器不会收到语言更改通知.因此,我将 registerObject:
调用移到了 init
方法中.
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
中取消注册很有意义.
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.当我写:
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'的显式消息发送
ARC forbids explicit message send of 'dealloc'
由于我需要调用 [super dealloc]
来确保超类正确清理,但 ARC 禁止这样做,我现在被卡住了.当我的对象即将死亡时,还有其他方法可以得到通知吗?
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,您只需不显式调用 [super dealloc]
- 编译器会为您处理它(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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