objective-c - 如何在 Objective-C 中创建一个 NSNotification 对象？

Question

我想创建一个 NSNotification 对象:

NSNotification *obj=[[NSNotification alloc]init];

但是当我这样创建时，我得到一个异常，因为“NSConcreteNotification init: is not allowed”。我该如何解决这个问题？

Answer 1

来自NSNotification文档:

You can create a notification object with the class methods notificationWithName:object: or notificationWithName:object:userInfo:. However, you don’t usually create your own notifications directly. The NSNotificationCenter methods postNotificationName:object: and postNotificationName:object:userInfo: allow you to conveniently post a notification without creating it first.