Calls the ParameterCollection.OnParametersChanged(EventArgs) method of the System.Web.UI.WebControls.ParameterCollection collection that contains the System.Web.UI.WebControls.Parameter object.
If the System.Web.UI.WebControls.Parameter object is not contained by a System.Web.UI.WebControls.ParameterCollection collection, calling the Parameter.OnParameterChanged method has no effect. If the System.Web.UI.WebControls.Parameter object is contained by a System.Web.UI.WebControls.ParameterCollection collection, Parameter.OnParameterChanged raises the ParameterCollection.ParametersChanged event of the collection.
If the System.Web.UI.WebControls.ParameterCollection collection is contained by a data source control, the ParameterCollection.ParametersChanged event raises the data source control's System.Web.UI.IDataSource.DataSourceChanged event, causing any data-bound controls to rebind.
Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.
The Parameter.OnParameterChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.