Dart 寻找provider context 的flutter问题

我对Flutter 翼提供程序模式有问题.用户重定向到新屏幕后，找不到提供程序.

根据我之前的问题(Could not find the correct provider above this widget)

class NewRoute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final title = 'Tap to select';
    return MaterialApp(
        title: title,
        home: Scaffold(
          appBar: AppBar(
            title: Text(title),
          ),
          body: NewRouteBody()
        ));
  }
}

class NewRouteBody extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    var user = Provider.of<UserRepository>(context);
    return ListView(...)

我做了同样的事情，但我再次得到一个错误，即它无法在这个小部件(NewRouteBody)上面找到正确的提供者.

我试着想办法解决这个问题，在谷歌上搜索了几个小时的答案，但没有成功……

感谢您的帮助.

EDIT个

这是包含图案的UserRepository:

class UserRepository with ChangeNotifier {
  User user;
  Status _status = Status.Uninitialized;

  Status get status => _status;
  User get getUser => user;
...}

EDIT 2:个

带有ChangeNotifier的代码段:

void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        primarySwatch: Colors.red,
      ),
      home: HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider<UserRepository>(
      builder: (context) => UserRepository.instance(),
      child: Consumer<UserRepository>(
        builder: (context, UserRepository userRepository, _) {
          switch (userRepository.status) {
            case Status.Uninitialized:
              return Login();
            case Status.Unauthenticated:
              return Login();
            case Status.Authenticating:
            case Status.Authenticated:

              if(userRepository.getUser.isPrefSet == 0){
                return Selection();
              }
              return Dashboard();
          }
        },
      ),
    );
  }
}