Hittest for LineSeries

Hi Jason,

Do we have a way to get hit test object on a LineSeries? When the mouse moves on a set of LineSeries in the Chart, I want to know which LineSeries it hits.

I tried to use hit test and it will not give me the proper HitTestResult.VisualHit object when the mouse pointer points on the line series.

Thanks, Gordon

Hello Gordon,

I will get back to you about this before the end of the week.

-Jason Fauchelle

Thanks, Jason

Gordon

Hi Gordon,

Thanks for waiting. The easiest way I've found to do this is to listen to mouse move events, and then check Mouse.DirectlyOver. For example, you could attach an event handler to the ChartMouseMove event of a Chart control:

<ms:Chart ChartMouseMove="Chart1_ChartMouseMove" />

And then in the event handler, do something like this:

private void Chart1_ChartMouseMove(object sender, ChartMouseEventArgs e)
{
  System.Windows.Shapes.Path path = Mouse.DirectlyOver as System.Windows.Shapes.Path;
  if (path != null)
  {
    LineSeries series = path.DataContext as LineSeries;
    if (series != null)
    {
      Debug.WriteLine(series.Title);
    }
  }
}

Mouse.DirectlyOver gives you the IInputElement where the mouse is. If this is a Path, simply check to see if the DataContext is a LineSeries. This approach will work with all of our line-based charts.

Let me know if you have further questions.

-Jason Fauchelle

thanks Jason.

I may be able to put up the tool tips for the line series now.

Gordon