Objective-C에서 NSNotificationCenter를 통해 메시지를주고 받습니까?

NSNotificationCenterObjective-C를 통해 메시지를 보내고 받으려고합니다 . 그러나이 작업을 수행하는 방법에 대한 예를 찾지 못했습니다. 메시지를 NSNotificationCenter어떻게 주고 받 습니까?

@implementation TestClass

- (void) dealloc
{
    // If you don't remove yourself as an observer, the Notification Center
    // will continue to try and send notification objects to the deallocated
    // object.
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    [super dealloc];
}

- (id) init
{
    self = [super init];
    if (!self) return nil;

    // Add this instance of TestClass as an observer of the TestNotification.
    // We tell the notification center to inform us of "TestNotification"
    // notifications using the receiveTestNotification: selector. By
    // specifying object:nil, we tell the notification center that we are not
    // interested in who posted the notification. If you provided an actual
    // object rather than nil, the notification center will only notify you
    // when the notification was posted by that particular object.

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

    return self;
}

- (void) receiveTestNotification:(NSNotification *) notification
{
    // [notification name] should always be @"TestNotification"
    // unless you use this method for observation of other notifications
    // as well.

    if ([[notification name] isEqualToString:@"TestNotification"])
        NSLog (@"Successfully received the test notification!");
}

@end

... 다른 수업 어딘가에 ...

- (void) someMethod
{

    // All instances of TestClass will be notified
    [[NSNotificationCenter defaultCenter] 
        postNotificationName:@"TestNotification" 
        object:self];

}

dreamlax의 예 를 확장하려면 ... 알림과 함께 데이터를 보내려면

게시 코드에서 :

NSDictionary *userInfo = 
[NSDictionary dictionaryWithObject:myObject forKey:@"someKey"];
[[NSNotificationCenter defaultCenter] postNotificationName: 
                       @"TestNotification" object:nil userInfo:userInfo];

코드를 관찰 할 때 :

- (void) receiveTestNotification:(NSNotification *) notification {

    NSDictionary *userInfo = notification.userInfo;
    MyObject *myObject = [userInfo objectForKey:@"someKey"];
}

이것은 나를 도왔다 :

// Add an observer that will respond to loginComplete
[[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(showMainMenu:) 
                                                 name:@"loginComplete" object:nil];


// Post a notification to loginComplete
[[NSNotificationCenter defaultCenter] postNotificationName:@"loginComplete" object:nil];


// the function specified in the same class where we defined the addObserver
- (void)showMainMenu:(NSNotification *)note {
    NSLog(@"Received Notification - Someone seems to have logged in"); 
}

출처: http://www.smipple.net/snippet/Sounden/Simple%20NSNotificationCenter%20example

블록을 사용할 가능성도 있습니다 :

NSOperationQueue *mainQueue = [NSOperationQueue mainQueue];
[[NSNotificationCenter defaultCenter] 
     addObserverForName:@"notificationName" 
     object:nil
     queue:mainQueue
     usingBlock:^(NSNotification *notification)
     {
          NSLog(@"Notification received!");
          NSDictionary *userInfo = notification.userInfo;

          // ...
     }];

애플의 문서

NSNotificationCenter를 사용하여 뷰를 업데이트하는 경우 다음을 호출하여 메인 스레드에서 뷰를 보내는 것을 잊지 마십시오 dispatch_async.

dispatch_async(dispatch_get_main_queue(),^{
    [[NSNotificationCenter defaultCenter] postNotificationName:@"my_notification" object:nil];
});

초보자를위한 선별 된 답변의 SWIFT 5.1

class TestClass {
    deinit {
        // If you don't remove yourself as an observer, the Notification Center
        // will continue to try and send notification objects to the deallocated
        // object.
        NotificationCenter.default.removeObserver(self)
    }

    init() {
        super.init()

        // Add this instance of TestClass as an observer of the TestNotification.
        // We tell the notification center to inform us of "TestNotification"
        // notifications using the receiveTestNotification: selector. By
        // specifying object:nil, we tell the notification center that we are not
        // interested in who posted the notification. If you provided an actual
        // object rather than nil, the notification center will only notify you
        // when the notification was posted by that particular object.

        NotificationCenter.default.addObserver(self, selector: #selector(receiveTest(_:)), name: NSNotification.Name("TestNotification"), object: nil)
    }

    @objc func receiveTest(_ notification: Notification?) {
        // [notification name] should always be @"TestNotification"
        // unless you use this method for observation of other notifications
        // as well.

        if notification?.name.isEqual(toString: "TestNotification") != nil {
            print("Successfully received the test notification!")
        }
    }
}

... 다른 수업 어딘가에 ...

 func someMethod(){
        // All instances of TestClass will be notified
        NotificationCenter.default.post(name: "TestNotification", object: self)
 }