if modify switch

[wolf-leo]

switch (drawerIndex) { case DrawerIndex.HOME: setState(() { screenView = const MyHomePage(); }); break; case DrawerIndex.Help: setState(() { screenView = HelpScreen(); }); break; case DrawerIndex.FeedBack: setState(() { screenView = FeedbackScreen(); }); break; case DrawerIndex.Invite: setState(() { screenView = InviteFriend(); }); break; default: break; }