刪除NSNotificationCenter觀察者

Question

我通過在ViewDidLoad中添加以下代碼來檢測鍵盤的顯示/隱藏：

[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(keyboardDidHide:) 
                                             name:UIKeyboardDidHideNotification 
                                           object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self 
                                         selector:@selector(keyboardWillShow:) 
                                             name:UIKeyboardWillShowNotification 
                                           object:nil];

盡管在某些時候我想刪除這些觀察者，而不用調用

 [[NSNotificationCenter defaultCenter] removeObserver:self];

因為這會刪除所有觀察者，並且我還有其他不想被刪除的觀察者。 如何只刪除這兩個？

Answer 1

[[NSNotificationCenter defaultCenter] removeObserver:self 
                                                name:UIKeyboardDidHideNotification 
                                              object:nil];

[[NSNotificationCenter defaultCenter] removeObserver:self 
                                                name:UIKeyboardWillShowNotification 
                                              object:nil];

Answer 2

使用官方文檔中所述的NSNotificationCentre的removeObserver:name:object:方法，以刪除特定通知名稱的觀察者。

Answer 3

使用[[NsNotificationCenter defaultCenter] removeObserver:self name: UIKeyboardWillShowNotification object:nil]