Tap into tooltips

I made my own overlay... worked great... but then I noticed that it was appearing off the scre开发者_运维知识库en (cut off).

I know silverlight has a tooltip control that auto positions itself on the screen instead of letting itself be cut off.

how can I tap into this control? or is there a better way?

<TextBlock>
    <ToolTipService.ToolTip>
        <ToolTip>
           <Overlay />  // This is you overlay
        </ToolTip>
    </ToolTipService.ToolTip>
</TextBlock>

You can put any content where <Overlay /> is. You can also apply this to any control, I just used a TextBlock for my example.