最初在UIView动画中调整UITextView帧大小时跳转

Question

我有以下代码来扩展文本区域＆amp;只要用户点击该字段，它就是超级视图。编辑开始：

- (void)textViewDidBeginEditing:(UITextView *)textView
{
    textView.text = @"";

    CGRect titleViewFrame = self.titleLabel.frame;
    titleViewFrame.size.height = kExpandedSubviewFrameHeight;

    CGRect titleTextViewFrame = self.titleTextView.frame;
    titleTextViewFrame.size.height = kExpandedSubviewFrameHeight;

    [UIView animateWithDuration:0.4f
        animations:^{
                         self.titleLabel.frame = titleViewFrame;
                         self.titleTextView.frame = titleTextViewFrame;
        }];
}

一切正常，除非用户第一次点击此字段，文本视图的y原点跳起来：

非常感谢任何帮助。

Answer 1

有点晚了但是我在调​​整uitextview时遇到了同样的问题，并认为它与滚动文本视图有关。这是我的代码，在动画高度时有0反弹。我使用NSLayoutConstraint来调整我的身高。

- (void)textViewDidChange:(UITextView *)textView
{
    CGSize size = [messageView sizeThatFits:CGSizeMake(messageView.frame.size.width, FLT_MAX)];
    [UIView animateWithDuration:0.4f
                     animations:^{
                         messageHeightConstraint.constant = size.height;
                         [self.view layoutIfNeeded];
                     }
                     completion:^(BOOL finished) {
                         [messageView scrollRangeToVisible:NSMakeRange([messageView.text length], 0)];
                     }
    ];

}