在目标c中注册课程 [英] register a class in objective c

问题描述

让我说我有classA这是一类音频，它对音频输入进行多次采样. 每次class A获得新数据(在一秒钟内可能发生很多次)，他都需要通知另一个类，即classB.

lets say i have classA which is a class of audio,that sample the audio input many times. each time class A get a new data (can happen many times in second), he needs to inform another class, which is classB.

现在，我可以在classA中创建class B的实例，并在收到新数据时调用B，但这不是模块化软件.

Now, i could just make an instance of class B in classA and call B when there is a new data arrived, but this is not a modular software.

我希望classA在外面是盲目的"，只是将他添加到每个项目中，并希望有另一个classB可以使他register某种方式，所以当A有新内容时，B会知道的((没有A呼叫B！)

i want classA to be "blind" to the outside, and just to add him to every project, and to have another classB that will register him some how, so when A has something new, B will know about it,(without A calling B ! )

它在目标c中是如何正确完成的?

how its done right in objective c ?

非常感谢.

推荐答案

您可以在ClassA中发布一个通知，并在其他类中对该通知进行 register (即ClassB).

You can post a notification in ClassA, and register for that notification in other classes (namely ClassB).

这是您可以执行的操作:

This is how you can do it:

(在ClassA中):

[[NSNotificationCenter defaultCenter]
 postNotificationName:@"noteName" object:self];

(在ClassB中):

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

每当ClassA实例发布新通知时，都会(立即)通知其他已向该通知注册的实例.在这种情况下，ClassB将执行doSomething:(NSNotification *)note.

Whenever an instance of ClassA posts a new notification, other instances that have registered to that notification will be informed (instantaneously). In this case, ClassB will perform doSomething:(NSNotification *)note.

您可以将该通知发布到您的设置方法(setVar:(NSString*)newVar).

You can post that notification your setter method (setVar:(NSString*)newVar).

如果您想传递一些东西，请使用postNotificationName:object:userInfo:变体. userInfo是NSDictionary，您可以在其中传递任何内容.例如:

If you want to pass something along, use the postNotificationName:object:userInfo: variant. userInfo is a NSDictionary and you can pass anything you want in it. for example:

NSDictionary* dic = [NSDictionary dictionaryWithObjectsAndKeys:var, @"variable", nil];
[[NSNotificationCenter defaultCenter]
postNotificationName:@"noteName" object:self userInfo:dic];

现在，编辑您的doSomething:方法:

-(void)doSomething:(NSNotification*)note {
    if ([[note name] isEqualToString:@"noteName"]) {
        NSLog(@"%@", [note userInfo]);
    }
}

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更多信息: https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Notifications/Introduction/introNotifications.html

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More info: https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Notifications/Introduction/introNotifications.html

https://developer.apple .com/library/mac/#documentation/General/Conceptual/DevPedia-CocoaCore/Notification.html

https://developer.apple .com/library/mac/#documentation/Darwin/Conceptual/MacOSXNotifcationOv/Introduction/Introduction.html

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