Keyboard Show/Hide Events

gistfile1.m

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    
    // キーボード表示・非表示イベント
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification
     
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification
                                               object:nil];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    
    // キーボード表示・非表示イベント
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIKeyboardWillShowNotification
                                                  object:nil];
    
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIKeyboardWillHideNotification
                                                  object:nil];
}


#pragma mark - Notification

- (void)keyboardWillShow:(NSNotification *)notification
{
    CGRect keyboardFrameEnd = [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    
    __weak typeof(self)weakSelf = self;
    [UIView animateWithDuration:0.3
                     animations:^{
                         CGRect frame = weakSelf.view.frame;
                         frame.origin.y = -(keyboardFrameEnd.origin.y / 4);
                         weakSelf.view.frame = frame;
                     }];
}

- (void)keyboardWillHide:(NSNotification *)notification
{
    __weak typeof(self)weakSelf = self;
    [UIView animateWithDuration:0.3
                     animations:^{
                         CGRect frame = weakSelf.view.frame;
                         frame.origin.y = 0.0;
                         weakSelf.view.frame = frame;
                     }];
}