ASP.NET 4 Unleashed

Sorting and Filtering Data

An instance of a chart control contains a DataManipulator property that can be used to sort and filter the chart data. You can sort any series in the chart by any axis (X, Y, Y2, and so on), and you can choose to sort in either an ascending or descending order. The DataManipulator property provides a Sort method to do this.

To use the sorting functionality, your chart must already be populated with data. To ensure this, we wait until the OnDataBound event to invoke our sorting code. Listing 15.3 sorts the movie categories from highest count to lowest count by executing the chtMovies_DataBound method after it binds to the SqlDataSource (see Figure 15.3).

Figure 15.3. Sorting a chart.

Listing 15.3. SortChart.aspx ...