The IDataSource.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. For example, the event is raised if a file name property, such as the System.Web.UI.WebControls.AccessDataSource.DataFile property, is changed on a file-based data source control.
For more information about handling events, see Consuming Events.