發送到實例的無法識別的選擇器resignFirstResponder

Question

我在我的應用程序中使用TPKeyboardAvoiding來在鍵盤顯示時隱藏移動文本字段，但在嘗試結束編輯文本字段時出現異常。它來自TPKeyboardAvoiding中的這種方法：

- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { 
    UIView* view =[self TPKeyboardAvoiding_findFirstResponderBeneathView:self]; 
    NSLog(@"%@",[view description]); 
    [view resignFirstResponder]; //this line gives the exception 
    [super touchesEnded:touches withEvent:event]; 
} 

我在這裏有點困惑。不應該所有的UIViews迴應resignFirstResponder？謝謝您的幫助。

完整的錯誤：

2014-03-25 17:40:39.919 Rysk[5553:70b] -[MenuViewController textFieldDidBeginEditing:]: unrecognized selector sent to instance 0xb63c820 

Answer 1

我解決了我的視圖控制器比包含TPKeyboardAvoidingScrollView實現UITextFieldDelegate協議的問題。最重要的是，這兩種方法：

- (void)textFieldDidBeginEditing:(UITextField *)textField{} 
- (void)textFieldDidEndEditing:(UITextField *)textField{} 

Answer 2

更新您的代碼如下：

- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { 
    UIView* view =[self TPKeyboardAvoiding_findFirstResponderBeneathView:self]; 
    NSLog(@"%@",[view description]); 
    if([view isKindOfClass:[UITextField class]]) { 
     UITextField *myTextField = (UITextField *)view; 
     [myTextField resignFirstResponder]; 
    } 
    [super touchesEnded:touches withEvent:event]; 
} 

Answer 3

試試這個簡單的方法....

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    //--Gesture to resign keyborad on touch outside 
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissKeyboard)]; 
    tap.cancelsTouchesInView = NO; 
    [self.view addGestureRecognizer:tap]; 
} 


//-- Resign keyboard on touch UIView 
-(void)dismissKeyboard 
{ 
    self.view.frame = CGRectMake(self.view.frame.origin.x, 0, self.view.frame.size.width, self.view.frame.size.height); 
    [self.view endEditing:YES]; 
} 

Answer 4

不知道如果你調用[yourTextField resignFirstResponder]以及。因此，有可能UITextField（在您提供的代碼中）不是此時的第一個響應者。我會建議調整你這樣的代碼：

- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { 
    UIView* view =[self TPKeyboardAvoiding_findFirstResponderBeneathView:self]; 

    if([view conformsToProtocol:@protocol(UITextFieldDelegate)] || [view conformsToProtocol:@protocol(UITextViewDelegate)]) && 
     [view isFirstResponder] && [view canResignFirstResponder]) 
    { 
     [view resignFirstResponder]; 
    } 

    [super touchesEnded:touches withEvent:event]; 
} 

另外，如果你使用的POD請確保您使用的是最新的版本，因爲我用的是一個在這種情況下是這樣的：

- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { 
    [[self TPKeyboardAvoiding_findFirstResponderBeneathView:self] resignFirstResponder]; 
    [super touchesEnded:touches withEvent:event]; 
} 

希望它有幫助！