基于用户角色的不同屏幕不起作用

Question

您好，我是 Flutter 的新手，正在制作一个预约应用程序，需要筛选两种类型的用户，即患者和医生。

 class DashboardPage extends StatefulWidget {
  @override
  _DashboardPageState createState() => _DashboardPageState();
}

class _DashboardPageState extends State<DashboardPage> {
  UserProvider userProvider;
  final AuthMethods _authMethods = AuthMethods();
  @override
  void initState() {
    super.initState();
  SchedulerBinding.instance.addPostFrameCallback((_) async {
  userProvider = Provider.of<UserProvider>(context, listen: false);
  await userProvider.refreshUser();

  _authMethods. getUserDetails();

});
}


  User user = User();
  @override
  Widget build(BuildContext context) {
      if (user.role == 'patient') {
        return PatientHomePage();
      }
      else if (user.role == 'doctor') {
        return DoctorHomePage();}
      return Container(color: Colors.red,);
  }
}

角色变量在另一个 dart 文件中定义：

class User {   String uid;   String name;   String email;   String role = "patient";   String profilePhoto;    User({     this.uid,     this.name,     this.email,     this.role,     this.profilePhoto,   });   ........... }

当用户登录时，默认值“患者”被分配给它。Future<void> addDataToDb(FirebaseUser currentUser) async { User user = User( uid: currentUser.uid, email: currentUser.email, name: currentUser.displayName, profilePhoto: currentUser.photoUrl, role: "patient"); firestore .collection(USERS_COLLECTION) .document(currentUser.uid) .setData(user.toMap(user)); }这一切都发生在另一个 dart 文件中

但是这个逻辑并没有按预期工作，因为它只在手机上显示红屏，这意味着 从 firebase 获取 user.role 存在一些问题。 请帮帮我...

Answer 1

class DashboardPage extends StatefulWidget {
 @override
 _DashboardPageState createState() => _DashboardPageState();
}

class _DashboardPageState extends State<DashboardPage> {
 UserProvider userProvider;
 final AuthMethods _authMethods = AuthMethods();
 User user = User();

 @override
 void initState() {
   super.initState();
   SchedulerBinding.instance.addPostFrameCallback((_) async {
     userProvider = Provider.of<UserProvider>(context, listen: false);
/// This method is future method so it might happen that after widget render you are getting response.
     await userProvider.refreshUser();

/// seState will rebuild your widget with new user details
     setState(() {
       user = _authMethods. getUserDetails();
     });

   });
 }


 @override
 Widget build(BuildContext context) {
   if (user.role == 'patient') {
     return PatientHomePage();
   }
   else if (user.role == 'doctor') {
     return DoctorHomePage();}
   return Container(color: Colors.red,);
 }
}