用键盘动画UIView

Question

我需要在即将开始的项目中添加聊天功能.

与此同时,我一直在努力实现我所期望的简单问题,即在屏幕底部有一个UIView,里面有一个UITextView,当用户点击UITextView时,它会用键盘设置动画.

我有它工作,但不幸的是键盘的动画略微落后于它上面的视图.这是我到目前为止的实现:

注册键盘通知:

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

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

键盘通知方法:

- (void)keyboardWillShow:(NSNotification*)notification
{
    CGFloat duration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
    NSInteger curve = [notification.userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue];

    [UIView animateWithDuration:duration delay:0 options:curve animations:^{

        CGRect keyboardFrame = [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
        _chatViewBottomConstraint.constant = keyboardFrame.size.height;
        [self.view layoutIfNeeded];

    } completion:nil];
}

有没有其他人做过类似的事情,能否为我提供更好的解决方案？

Answer 1

这对我有用:

- (void)keyboardWillShow:(id)keyboardDidShow
{
    [UIView beginAnimations:nil context:NULL];

    NSDictionary *userInfo = [keyboardDidShow userInfo];
    [UIView setAnimationDuration:[userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
    [UIView setAnimationCurve:[userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue]];
    [self.view layoutIfNeeded];

    [UIView commitAnimations];
}

- (void)keyboardWillHide:(id)keyboardDidHide
{
    [UIView beginAnimations:nil context:NULL];

    NSDictionary *userInfo = [keyboardDidHide userInfo];
    [UIView setAnimationDuration:[userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
    [UIView setAnimationCurve:[userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue]];            
    [self.view layoutIfNeeded];

    [UIView commitAnimations];
}

更新: 或者你可以用块做同样的事情:

- (void)keyboardWillShow:(id)keyboardDidShow
{
    NSDictionary *userInfo = [keyboardDidShow userInfo];
    [UIView animateWithDuration:[userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]
                          delay:0.f
                        options:[[keyboardDidShow userInfo][UIKeyboardAnimationCurveUserInfoKey] intValue] << 16
                     animations:^{
        ...
    } completion:^(BOOL finished) {
        ...
    }];
}

- (void)keyboardWillHide:(id)keyboardDidHide
{
    NSDictionary *userInfo = [keyboardDidHide userInfo];
    [UIView animateWithDuration:[userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]
                          delay:0.f
                        options:[[keyboardDidHide userInfo][UIKeyboardAnimationCurveUserInfoKey] intValue] << 16
                     animations:^{
        ...
    } completion:^(BOOL finished) {
        ...
    }];
}

Answer 2

通知userInfo词典具有动画duration(UIKeyboardAnimationDurationUserInfoKey)和curve(UIKeyboardAnimationCurveUserInfoKey)信息; 如果同时使用它们,则动画应与键盘动画时序相匹配.