ios - Objective C View 不随键盘移动

Question

我在应用程序的 TextView 上使用以下代码。我已经做到了，当键盘触发时， View 将上升到键盘顶部，当我单击键盘和 TextView 之外时，它将关闭键盘。我遇到的问题是，当我单击 TextView 时， TextView 在键盘顶部移动大约 5 秒，然后弹出，而且当我单击关闭键盘时，它会立即消失并且不会像动画一样键盘确实打开了。有什么方法可以解决这个问题，并使 View 在键盘打开和关闭时在键盘顶部移动而不是跳跃？

谢谢

- (void)viewDidLoad
{
    [super viewDidLoad];
    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
    [center addObserver:self selector:@selector(didShow:) name:UIKeyboardDidShowNotification object:nil];
    [center addObserver:self selector:@selector(didHide) name:UIKeyboardWillHideNotification object:nil];


        _theTextView.delegate = self;
    _theTextView.text = @"Type your message..";
    _theTextView.textColor = [UIColor lightGrayColor]; //optional
    _theTextView.layer.cornerRadius = 5;
    _theTextView.layer.masksToBounds = YES;
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]
                                   initWithTarget:self
                                   action:@selector(dismissKeyboard)];

    [self.view addGestureRecognizer:tap];

}

-(void)dismissKeyboard {
    [_theTextView resignFirstResponder];
}
- (void)didShow:(NSNotification *)notification
{
    CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    self.textViewPOS.constant = keyboardSize.height;

    NSLog(@"Opened");
}

- (void)didHide
{
     self.textViewPOS.constant = 0;
    NSLog(@"Closed");
}

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    NSLog(@"typing");
    return YES;
}
- (void)textViewDidBeginEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@"Type your message.."]) {
        textView.text = @"";
        textView.textColor = [UIColor blackColor]; //optional
    }
    [textView becomeFirstResponder];
}
- (void)textViewDidEndEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@""]) {
        textView.text = @"Type your message..";
        textView.textColor = [UIColor lightGrayColor]; //optional
    }
    [textView resignFirstResponder];
}

@end

Answer 1

对于延迟问题，您可以按照 Eugene Zaychenko 的建议使用 UIKeyboardWillShowNotification 。它会解决你的问题。

[center addObserver:self selector:@selector(willShow:) name:UIKeyboardWillShowNotification object:nil];

对于动画，请使用以下代码

- (void)didHide
{
    self.textViewPOS.constant = 0;
    NSLog(@"Closed");

    [UIView animateWithDuration:1 delay:0 options:0 animations:^{

        self.textViewPOS.constant = 0;
        [self.view layoutIfNeeded];

    } completion:nil];

}

- (void)willShow:(NSNotification *)notification
{
    CGSize keyboardSize = [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;

    [UIView animateWithDuration:1 delay:0 options:0 animations:^{

        self.textViewPOS.constant = keyboardSize.height;
        [self.view layoutIfNeeded];

    } completion:nil];

    NSLog(@"Opened");
}

如果有任何疑问，请告诉我。