刪除NSNotificationCenter觀察者

Question

我加入這個代碼在viewDidLoad中檢測鍵盤的顯示/隱藏：

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

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

在某些時候，雖然我想刪除這些觀察員，而不調用

[[NSNotificationCenter defaultCenter] removeObserver:self]; 

，因爲這會刪除所有觀察者，並且我有其他觀察員不希望被刪除。我怎樣才能刪除這兩個？

Answer 1

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

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

Answer 2

使用的的removeObserver:name:object:方法如所描述的in the official documentation，以除去觀察者用於特定通知名稱。

Answer 3

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