public void OnDeleteWithoutSaveCommand(object param) { DiagramVM diag = param as DiagramVM; int index = Diagrams.IndexOf(diag); Diagrams.Remove(diag); if (diag.IsSelected && Diagrams.Count > 0) { if (Diagrams.Count == index) { Diagrams[index - 1].IsSelected = true; } else if (Diagrams.Count > index) { Diagrams[index].IsSelected = true; } } if (Diagrams.Count == 0) { Exit.Execute(null); } }