未处理的异常：处理后使用了一个类。 - 颤振

Question

我收到了这个错误

E/flutter ( 9610): [ERROR:flutter/lib/ui/ui_dart_state.cc(166)] Unhandled Exception: A CustRegViewModel was used after being disposed.
E/flutter ( 9610): Once you have called dispose() on a CustRegViewModel, it can no longer be used.

我有一个名为CustRegView 的视图，我从用户那里获取电话号码并将其发送给ViewModel 命名为 CustRegViewModel 进行身份验证，根据其身份验证状态返回 bool。

class CustRegView extends StatefulWidget {
  @override
  _CustRegViewState createState() => _CustRegViewState();
}

class CustRegView extends StatelessWidget{
  final TextEditingController _controller = TextEditingController();

  @override
  Widget build(BuildContext context) {
    final deviceSize = MediaQuery.of(context).size;
    return BaseView<CustRegViewModel>( 
          builder: (context, model, child) => Scaffold(
    
    ...<some code>
    
    FlatButton (
        onPressed: () async {
            var registerSuccess = await model.register( _controller.text, context);   
           // ^^^^^ HERE, IN ABOVE LINE, I'M GETTING AN ERROR ^^^^^^
                                
            if (registerSuccess) {
                Navigator.pushNamed(context, 'newScreen');
            } else {
                UIHelper().showErrorButtomSheet(context, model.errorMessage);
            }
    )
}

CustRegViewModel 看起来像这样

class CustRegViewModel extends BaseViewModel {
    
    final AuthService _authService = locator<AuthService>();
    final DialogService _dialogService = locator<DialogService>();
    dynamic newUserResult; 
    dynamic verifyResult;

    Future<bool> register(String phoneNo, BuildContext context) async {
        await verifyPhone;
        return    verifyResult ? true :  false;  // From here it returns true
    }

    Future<void> verifyPhone(phoneNo) async {

            await FirebaseAuth.instance.verifyPhoneNumber(
                    phoneNumber: updatedPhoneNo,
                    timeout: Duration(seconds: 50),
                    verificationCompleted: (AuthCredential authCred) async {...... <some code>
                    verificationFailed: (AuthException authException) {...... <some code>
                    codeSent: (String verID, [int forceCodeResend]) async {...... <some code>
                    codeAutoRetrievalTimeout: (String verID) {...
             ).catchError((error) {...... <some code>
    }
}

BaseView 看起来像这样

class BaseView<T extends BaseViewModel> extends StatefulWidget {
  final Widget Function(BuildContext context, T model, Widget child) builder;
  final Function(T) onModelReady;
  BaseView({this.builder, this.onModelReady});
  @override
  _BaseViewState<T> createState() => _BaseViewState<T>();
}

class _BaseViewState<T extends BaseViewModel> extends State<BaseView<T>> {
  T model = locator<T>();

  @override
  void initState() {
    if (widget.onModelReady != null) {
      widget.onModelReady(model);
    }
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider<T>(
      create: (context) => model,
      child: Consumer<T>(builder: widget.builder),
    );
  }
}

BaseViewModel 看起来像这样

class BaseViewModel extends ChangeNotifier {
  ViewState _state = ViewState.Idle;


  ViewState get state => _state;

  void setState(ViewState viewState) {
    _state = viewState;
    notifyListeners();
  }
}

Answer 1

您可能在依赖注入中使用了 RegisterLazySingleton 而不是 Factory。