TextView 文本未正确显示

Question

我使用自动布局。我有一个TextView 有其他意见。当键盘出现时，部分 TextView 隐藏在键盘后面。因此，我通过降低其底部约束（及其父视图的底部）来降低其高度，以便用户可以滚动并查看整个文本。

但问题是当键盘消失时，TextView 的文本只有一半可见。但是当我点击它时，它会显示整个文本。

正常的样子：

键盘出现后的样子：

键盘消失后的样子：

现在，如果我点击TextView，它看起来与第一张图片相同。即完整的文本可见：

代码： self.messageView 是 TextView。

// Called when keyboard is going to be displayed
- (void)keyboardWillShow:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];

    // get animation info from userInfo
    NSTimeInterval animationDuration;
    CGRect keyboardFrame;
    [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&animationDuration];
    [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] getValue:&keyboardFrame];

    // Save constant to set back later
    self.bottomConstant = self.noticeMessageBottom.constant;

    // Change bottom space constraint's constant
    self.noticeMessageBottom.constant = keyboardFrame.size.height + 8.0f;

    [UIView animateWithDuration:animationDuration delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{

        [self.messageView setNeedsLayout];
        [self.messageView layoutIfNeeded];

        [self.view setNeedsLayout];
        [self.view layoutIfNeeded];
    } completion:nil];

    [self.messageView flashScrollIndicators];
}

// Called when keyboard is going to be hidden
- (void)keyboardWillHide:(NSNotification*)aNotification
{
    NSDictionary* info = [aNotification userInfo];

    // get animation info from userInfo
    NSTimeInterval animationDuration;
    CGRect keyboardFrame;
    [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&animationDuration];
    [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] getValue:&keyboardFrame];

    // Reset contentOffset
    self.messageView.contentOffset = CGPointZero;

    // Change bottom space constraint's constant
    self.noticeMessageBottom.constant = self.bottomConstant;

    [UIView animateWithDuration:animationDuration delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{

        [self.messageView setNeedsLayout];
        [self.messageView layoutIfNeeded];

        [self.view setNeedsLayout];
        [self.view layoutIfNeeded];
    } completion:nil];
}

注意：仅当TextView 的contentOffset 是(0,0) 时才会发生这种情况。即用户没有滚动它或滚动回顶部。如果用户滚动它并且contentOffset 不是(0,0) 那么它工作正常。

Answer 1

我只是在情节提要中取消选中 TextView 的滚动启用属性，它不再出现该问题。