![Shows a graphic of how someone might associate their data using the chart's drilldown functionality.](Images/Chart_Introduction_to_Drill_Down_01.png)
Chart provides the ability to associate detailed data with displayed chart elements. This heightened degree of detail is hidden from users until they click on an associated chart element of interest. The detailed data is then presented in-place by another chart (which may be of a different chart type if that better suits the data). This process of navigating data to greater depths is called drilling down.
As an example of drill down’s benefit to your audience, consider the scenario of a presentation of a company’s Sales results to financial analysts. At the top-level of this presentation the chart presents Annual Sales for the past several fiscal years in a column chart. The user clicks on any given year’s column to drill down into the Quarterly Sales.
Additional detail may be provided on domestic and international markets. When the user delves into a particular Quarter’s sales data, they can be presented with a pie chart of sales revenue by continent. Drill down may continue breaking down sales by individual country, product, or any other criteria.
At any point users may drill back up the hierarchy of detailed data, diving into only that information in which they are interested, in a convenient and intuitive manner.
Developers can drill-enable Chart by providing:
Child chart type.
Data source to be used in presenting the child chart.
Identity of row and column of chart element from parent chart that is drillable.
An optional callback by implementing the IDrillDown interface.