UITextView光标/滚动移动问题

Question

我使用UITextView进行聊天，就像这里附带的截图一样。

但问题是如果我按下键盘的返回键，光标不会粘在UITextView边界的底部。我也使用了以下代码：

- (void)textViewDidChange:(UITextView *)textView
{
    if([textView contentSize].height <80.0)
    {
        CGFloat textHeight         = [self textHeightForTextView:textView];

        CGFloat newViewHeight = MAX(MIN(textHeight, 80.0), 33.0);

        chatTxtHeightConstraint.constant = newViewHeight;

        [textView scrollRangeToVisible:textView.selectedRange];
    }
}

任何解决方案？

Answer 1

我通过编写[textView layoutIfNeeded];和[textView updateConstraints];以下代码行chatTxtHeightConstraint.constant = newViewHeight;来解决问题

- (void)textViewDidChange:(UITextView *)textView
{
    if([textView contentSize].height <80.0)
    {
        CGFloat textHeight         = [self textHeightForTextView:textView];

        CGFloat newViewHeight = MAX(MIN(textHeight, 80.0), 33.0);

        chatTxtHeightConstraint.constant = newViewHeight;

        [textView layoutIfNeeded];
        [textView updateConstraints];

        [textView scrollRangeToVisible:textView.selectedRange];
    }
}