Chart does not provide you a simple way to get the intersection point but it has everything you need to do that yourself. You can calculate the position of all the data points in pixels and then using a simple math calculate the intersection points. Then you can apply the opposite transformation from pixels to axes values.

The trick is that you need to use one of the chart events when position of all chart elements is already calculated. For example, PrePaint event. Use chart Axis methods PixelPositionToValue and ValueToPixelPosition to do the conversion.

Alex.

http://blogs.msdn.com/alexgor