发布两个 NSNotification 时的执行顺序

发布于 2024-10-20 01:02:20 字数 929 浏览 11 评论 0原文

关于 NSNotification 的一个简单问题...如果我在一个方法中发布两个 NSNotification，并且它们被不同的对象观察，那么选择器方法的执行顺序是什么？

例如，如果我有三个控制器 - Poster、Receiver A 和 Receiver B。在 Poster 控制器的函数中，我执行以下操作：

[[NSNotificationCenter defaultCenter] postNotificationName:@"ReceiverADoSomething" object:self];
[[NSNotificationCenter defaultCenter] postNotificationName:@"ReceiverBDoSomething" object:self];

在接收器 A 的 viewDidLoad 方法中：

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(workToDoByA:) name:@"ReceiverADoSomething" object:nil];

在接收器 B 的 viewDidLoad 方法中：

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(workToDoByB:) name:@"ReceiverADoSomething" object:nil];

Will 先完成workToDoByA，然后再完成workToDoByB？还是一起被处决？

另一种情况...如果我让海报 A 发布通知，但同一个通知有两个观察者。那么执行顺序是怎样的呢？

预先感谢您的帮助。

原文

A quick question about NSNotification... If I post two NSNotifications in a method, and they are observed by different objects, what is the sequence of execution of the selector method?

For instance, if I have three controllers - Poster, Receiver A and Receiver B. In a function of the Poster controller, I do the following:

[[NSNotificationCenter defaultCenter] postNotificationName:@"ReceiverADoSomething" object:self];
[[NSNotificationCenter defaultCenter] postNotificationName:@"ReceiverBDoSomething" object:self];

In the viewDidLoad method for receiver A:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(workToDoByA:) name:@"ReceiverADoSomething" object:nil];

In the viewDidLoad method for receiver B:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(workToDoByB:) name:@"ReceiverADoSomething" object:nil];

Will workToDoByA be done first followed by workToDoByB?
Or they will be executed together?

Another scenario... If I have Poster A posting a notification but there are two observers to the SAME notification. What is the execution sequence then?

Thanks in advance for your help.

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