The PropertyGrid control may display a number of different System.Windows.Forms.Design.PropertyTab panes. When the tab changes, the grid raises PropertyGrid.PropertyTabChanged , and this class encapsulates the data for that event. You can retrieve the NewTab (to which the grid is about to change) and the OldTab (from which the grid is about to change). public class PropertyTabChangedEventArgs : EventArgs { // Public Constructors public PropertyTabChangedEventArgs (System.Windows.Forms.Design.PropertyTab oldTab , System.Windows.Forms.Design.PropertyTab newTab ); // Public Instance Properties public PropertyTab NewTab {get; } public PropertyTab OldTab {get; } } HierarchySystem.Object System.EventArgs PropertyTabChangedEventArgs Passed ToPropertyGrid.OnPropertyTabChanged() , PropertyTabChangedEventHandler.{BeginInvoke() , Invoke()} |