向上折叠后如何显示UIElement？

Question

On my form, I have a TextBlock element that initially is collapsed. ( TextBlock.Visibility = Visibility.Collapsed ). When some error occurred, it should be shown. When I use TextBlock.Visibility = Visibility.Show , all the controls that are situated under the TextBlock , are getting down.

Question: How to dock all the elements that are situated under this TextBlock in such a way that in case when the TextBlock is shown, to lift the upper elements?

Answer 1

One way to achieve that is through strategic use of the VerticalAlignment property. Consider the following snippet. If this stackpanel is in a container where it has room to grow, it will grow upwards. When you toggle the visibility on the middle textblock, then, it will push the elements above it.

<StackPanel VerticalAlignment="Bottom">
    <TextBlock>I shift upward</TextBlock>
    <TextBlock Visibility="Collapsed">Error message here</TextBlock>
    <TextBlock>I stay put</TextBlock>
</StackPanel>

Answer 2

我不确定您要问的是什么，但是如果您不希望在TextBlock可见时其他控件移动，那么它应该以Visibility.Hidden开头。