i can get itemclick by left click on chart, it's cool.
but we need a function of the right click, it seems the right click do not have eventargs like left click.
is there any way to solve this?

I believe i got this problem solved, not perfect but works.

_chart.DefaultView.ChartArea.HoverChanged += new EventHandler<ChartHoverChangedEventArgs>(ChartArea_HoverChanged);

Use this to save the datapoint hover.

_chart.DefaultView.ChartArea.MouseRightButtonDown += new MouseButtonEventHandler(ChartArea_MouseRightButtonDown);

In this read the data mouse hovered.

But the important thing is, you have to set the selectionmode to item, not series!

Hello Tony,

You don't need to use the HoverChanged event of the ChartArea to achieve this. Instead you can just use the ChartArea.HoveredItems collection straight in the MouseRightButtonDown event handler. Here is an example: 

All the best,
Petar Kirov
the Telerik team