개체가 자체 알림을 구독 할 수 있습니까?

Question

예를 들어, a UITextField cannot be its own delegate이지만 자체 알림의 옵저버로 등록하면 되나요? 이상하게 보이지만 잘 작동하는 것 같습니다. 생각? 당신이 무슨 일을하는지

// MyTextField.h 

@interface MyTextField : UITextField 
@end 

// MyTextField.m 

@interface MyTextField() 
- (void)myTextFieldDidChange:(NSNotification *)notification; 
@end 

@implementation MyTextField 

- (void)dealloc { 
    [[NSNotificationCenter defaultCenter] removeObserver:self]; 
} 

- (id)initWithFrame:(CGRect)frame { 
    self = [super initWithFrame:frame]; 
    if (self) { 
     [[NSNotificationCenter defaultCenter] 
     addObserver:self 
     selector:@selector(myTextFieldDidChange:) 
     name:UITextFieldTextDidChangeNotification 
     object:self]; 
    } 
} 

- (void)myTextFieldDidChange:(NSNotification *)notification { 
    // Do custom stuff here. 
} 

@end 

Answer 1

잘 보이지만,이 특정 예를 들어, 순수한 해결 방법이 있습니다 :

// MyTextField.h 

@interface MyTextField : UITextField 
@end 

// MyTextField.m 

@interface MyTextField() 
- (void)myTextFieldDidChange:(UITextField *)textField; 
@end 

@implementation MyTextField 

- (id)initWithFrame:(CGRect)frame { 
    self = [super initWithFrame:frame]; 
    if (self) { 
     [self addTarget:self action:@selector(myTextFieldDidChange:) 
     forControlEvents:UIControlEventEditingChanged]; 
    } 
    return self; 
} 

- (void)myTextFieldDidChange:(MyTextField *)myTextField { 
    // Do custom stuff here. 
} 

@end 

체크 아웃 UIControlEvents reference은.