Data Source Control. IHierarchical Data Source. Data Source Changed Event
Occurs when the HierarchicalDataSourceControl has changed in some way that affects data-bound controls.
event EventHandler System.Web.UI.IHierarchicalDataSource.DataSourceChanged;
Custom Event DataSourceChanged As EventHandler Implements System.Web.UI.IHierarchicalDataSource
The DataSourceChanged event is raised when the properties of a data-bound control or the underlying data has changed in some way that affects the data bindings between a data-bound control and its data.