This class encapsulates the data for the PropertyGrid.SelectedGridItemChanged event. You can retrieve both the OldSelection and the NewSelection . public class SelectedGridItemChangedEventArgs : EventArgs { // Public Constructors public SelectedGridItemChangedEventArgs (GridItem oldSel , GridItem newSel ); // Public Instance Properties public GridItem NewSelection {get; } public GridItem OldSelection {get; } } HierarchySystem.Object System.EventArgs SelectedGridItemChangedEventArgs Passed ToPropertyGrid.OnSelectedGridItemChanged() , SelectedGridItemChangedEventHandler.{BeginInvoke() , Invoke()} |