颤振路由will_pop_scope错误，但是一次

Question

嗨，我正在使用Drawer路由菜单。它可以正常工作2页，但是有一页给出了错误。

当我第一次按菜单时，菜单正常工作，然后当我转到另一页并返回时，出现此错误

我也尝试过在mainApp buut上使用路由进行路由，这对我来说似乎更容易

我的抽屉

class MyDrawer extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _MyDrawerState();
}

class _MyDrawerState extends State {
  @override
  Widget build(BuildContext context) {
    return Drawer(
      child: ListView(
        children: <Widget>[
          DrawerHeader(
            child: Align(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[                  
                  Text(
                    "Test",
                    style: TextStyle(color: Colors.white, fontSize: 25.0),
                  ),
                ],
              ),
            ),
            decoration: BoxDecoration(
              color: Colors.blue,
            ),
          ),
          ListTile(
            leading: Icon(Icons.home),
            title: Text('Main'),
            trailing: Icon(Icons.arrow_right),
            onTap: () {
              Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => Main(),
                  ));
            },
          ),
          ListTile(
            leading: Icon(Icons.perm_device_information),
            title: Text('How'),
            trailing: Icon(Icons.arrow_right),
            onTap: () {
              //Navigator.pushNamed(context, "/how");
              Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => HowItWorks(),
                  ));
            },
          ),  
          ListTile(
            leading: Icon(Icons.keyboard),
            title: Text('Contact'),
            trailing: Icon(Icons.arrow_right),
            onTap: () {
              //Navigator.pushNamed(context, "/contact");
              Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => SendMail(),
                  ));
            },
          ),
          
        ],
      ),
    );
  }
}