Question

我需要在即将开始的项目中添加聊天功能。

与此同时，我一直在尝试实现我所期望的简单问题，即在屏幕底部有一个UIVeiew，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];
}

有没有其他人做过相似的事情，能够为我提供更好的解决方案吗？

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];
}

<强>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词典包含动画持续时间（UIKeyboardAnimationDurationUserInfoKey）和曲线（UIKeyboardAnimationCurveUserInfoKey）信息;如果你使用两者，你的动画应该与键盘动画时间匹配。

用键盘动画UIView

2 个答案: