Sparkline lets you add a tooltip to provide some extra information in a pop-up box. The pop-up box appears every time you hover over the Sparkline. It can be used to display useful information about the data points used for plotting the sparkline.

To add a tooltip to the sparkline, add the following code.

<c1:C1Sparkline.ToolTip>
    <ToolTip>
        Sparkline Type: Line
    </ToolTip>
</c1:C1Sparkline.ToolTip>

sparkline.ToolTip = "Sparkline Type: Line";