title: C# MSChart add hover Line
body: <p>When you click into a mschart a red line appears, is it somehow possible to add this line while hovering over the chart? I would like to make this line visible while hovering and add the result of the hovered datapoint under the line or something like that. So far I only found out about tooltip and was able to use it and show values of datapoint while hovering over it.<br>
  If you dont know about what line I'm talking:<br>
  <a href="https://i.stack.imgur.com/XEYw9.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XEYw9.jpg" alt="enter image description here"></a></p>