How to set telerik chart TrackBall position programatically

Question

I have created a custom control which has Telerik RadCartesianChart. This custom control creates any number of charts based on user dropdown selection. The number of charts on screen can vary but all have same x axis. I added a chart track ball line on custom control which is working fine on one chart on mouse movement. I want to add the same track ball line on all of the other chart on window so that movement on one track ball would reflect the same position on the other charts. How could I implement this behavior programmatically?

Answer 1

I don't know if you can do what you are attempting without adding a ChartTrackBallController to every chart.

What I'd suggest is adding multiple series to the one chart, share the X axis but have multiple Y axes as required. This way the ChartTrackBallController will pick a point on all series in the chart.

    // Trackball
    ChartTrackballController ctbcMain = new ChartTrackballController();
    ctbcMain.TextNeeded += ctbcMain_TextNeeded;
    ctbcMain.InnerPointSize = new SizeF(0, 0);
    ctbcMain.OuterPointsSize = new SizeF(0, 0);
    rcvUPM.Controllers.Add(ctbcMain);
    rcvUPM.ShowTrackBall = true;

In the above code snippit, rcvUPM is a radchartview containing all the data series you want to show, and ctbcMain_TextNeeded is used to customise the content of what the hover for the trackball shows.

It seems that by default the hover content will contain multiple points from each series, even after the InnerPointSize and OuterPointsSize was set to zero on advice by Telerik support a LINQ FirstOrDefault was needed on the collection of DataPointInfo objects to limit it to one point per series.