如何使用Reactive Cocoa和通知 [英] How to use Reactive Cocoa with notifications

问题描述

如何从通知名称中创建信号？例如，我想来自：

How can I create a signal out of a notification name? For example, I want to go from:

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(userDidChange:)
                                             name:kTTCurrentUserLoggedOffNotification
                                           object:nil];

类似于：

[signalForName(kTTCurrentUserLoggedOffNotification) subscribeNext:^(id x){
...
}];

推荐答案

- [NSNotificationCenter rac_addObserverForName： object：] 返回无限信号。你可以这样订阅

-[NSNotificationCenter rac_addObserverForName:object:] returns an infinite signal. You can subscribe to it like this

Objective-c

[[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIApplicationDidEnterBackgroundNotification object:nil]
  takeUntil:[self rac_willDeallocSignal]]
  subscribeNext:^(id x) {
     NSLog(@"Notification received");
}];

Swift

NSNotificationCenter.defaultCenter()
  .rac_addObserverForName(UIKeyboardWillShowNotification, object: nil)
  .takeUntil(self.rac_willDeallocSignal())
  .subscribeNext { (_) in
     print("Notification received")
  }

---

此信号如无限所述。如果您需要此信号/订阅绑定到 self 的生命周期，您可以使用<$ c添加 takeUntil： $ c> rac_willDeallocSignal 喜欢这样：

---

This signal is as stated infinite. If you need this signal/subscription to be bound to the lifetime of self you can add takeUntil: with rac_willDeallocSignal like this:

Objective-c

[[[[NSNotificationCenter defaultCenter] rac_addObserverForName:UIApplicationDidEnterBackgroundNotification object:nil]
  takeUntil:[self rac_willDeallocSignal]]
  subscribeNext:^(id x) {
     NSLog(@"Notification received");
}];

Swift

NSNotificationCenter.defaultCenter()
  .rac_addObserverForName(UIKeyboardWillShowNotification, object: nil)
  .takeUntil(self.rac_willDeallocSignal())
  .subscribeNext { (_) in
     print("Notification received")
  }

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