Absolute positioning in WPF

Question

I have a long text and show first sentence in a TextBlock. I wish by clicking the TextBlock or a button to show a panel below the TextBlock with full text. I wish this panel be absolutely positioned and be displayed above any other elements, you can do a similar thing in HTML showing and hiding absolutely positioned 'div' element. How to do this in WPF? Thank you for any suggestions.

Answer 1

Put the long text in an AdornerLayer is the best option. Check out some links http://msdn.microsoft.com/en-us/library/ms743737.aspx http://wangmo.wordpress.com/2008/10/19/relations-between-adorner-adornerlayer-and-adornerdecorator/

Answer 2

AdornerLayer can work, but may be a little complex. Other options include using PopUps or ToolTips -- you should look into those first as your easiest options.

If these all don't work, it'll really depends on what kind of panel you're using. For example, if you're using a Canvas, all you have to do is make sure to set the correct ZIndex on the element.

In order to make this more robust, I'd suggest the following:

<!-- Set Panel.ZIndex="99" when showing hidden area to ensure top placement -->
<Grid>
  <TextBlock>This is my primary bit of text ...</TextBlock>

  <!-- Canvas stays hidden until we want to show the rest of the text -->
  <Canvas Visibility="Hidden">
    <TextBlock Canvas.Bottom="-10">Content goes here</TextBlock>
  </Canvas>
</Grid>