颤动验证(BLoC pattern & rxDart)？

Question

如何在登录页面上显示错误消息？

这是我创建的Bloc：

class LoginBloc extends Object with Validators{
  final _repository = EresidenceRepository();
  final _userid = BehaviorSubject<String>();
  final _password = BehaviorSubject<String>();
  final _imei = BehaviorSubject<String>();
  final _coordinate = BehaviorSubject<String>();
  final BehaviorSubject<ApiResponse<login_responses>> _subject = BehaviorSubject<ApiResponse<login_responses>>();

  Function(String) get userid => _userid.sink.add;
  Function(String) get password => _password.sink.add;
  Function(String) get imei => _imei.sink.add;
  Function(String) get coordinate => _coordinate.sink.add;

  Stream<String> get useridValidation => _userid.stream.transform(useridValidator);
  Stream<String> get passwordValidation => _password.stream.transform(passwordValidator);
  Stream<bool> get submitCheck => Rx.combineLatest2(useridValidation, passwordValidation, (e,p) => true);

  login() async {
    try {
      login_responses response = await _repository.login(
          _userid.value, _password.value, _imei.value, _coordinate.value);
      _subject.sink.add(ApiResponse.completed(response));

      prefsBloc.changePrefsLogin(
          PrefsState(false, response.data.userid, response.data.password, _imei.value, _coordinate.value)
      );

      print(_imei.value + " " + _coordinate.value);
      print(response);

    } catch (e) {
      _subject.sink.add(ApiResponse.error(e.toString()));
      print(e);
      print(_userid.value);
    }
  }

  dispose(){
    _userid.close();
    _password.close();
    _imei.close();
    _coordinate.close();
    _subject.close();
  }

  BehaviorSubject<ApiResponse<login_responses>> get subject => _subject;

}

final login = LoginBloc();

我已经尝试过像我的UI代码这样的方法，但在黑色背景上出现了一条错误消息。在错误状态期间，我尝试显示错误消息。我想在登录页面/登录表单上显示一条错误消息。你是怎么做到的？

希望有谁能帮我

用户界面：

 @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: StreamBuilder<ApiResponse<login_responses>>(
          stream: login.subject,
          builder: (context, snapshot){
            if(snapshot.hasData) {
              switch (snapshot.data.status) {
                case Status.LOADING:
                  break;
                case Status.COMPLETED:
                  login_responses result = snapshot.data.data;
                  print(result.data.password + " " +result.data.userid);
                  AppRoutes.push(context, OtpLoginPage());
                  break;
                case Status.ERROR:
                  return CupertinoAlertDialog(
                    title: Text(snapshot.data.message),
                    actions: <Widget>[
                      CupertinoDialogAction(
                        child: Text('OK'),
                        onPressed: () {
                          Navigator.of(context).pop();
                        },
                      ),
                    ],
                  );
                  break;
              }
            }
            print("FORM LOGIN");
            return _formLogin();
          }
      ),
    );
  }
_formLogin() {
    return AnnotatedRegion<SystemUiOverlayStyle>(
      value: SystemUiOverlayStyle.dark,
      child: Material(
          color: Colors.white,
          child: SafeArea(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                Expanded(
                    flex: 1,
                    child: Container(
                        padding: EdgeInsets.symmetric(horizontal: SizeConfig.widthMultiplier * 1, vertical: SizeConfig.heightMultiplier * 1),
                        child: CachedNetworkImage(
                          imageUrl: "",
                          placeholder: (context, url) => CircularProgressIndicator(),
                          errorWidget: (context, url, error) => Icon(Icons.broken_image),
                          fit: BoxFit.fill,
                        ),
                    )
                ),
                Expanded(
                    flex: 2,
                    child: Container(
                        padding: EdgeInsets.all(SizeConfig.heightMultiplier * 2),
                        child: Column(
                          children: <Widget>[
                            Container(
                                child: StreamBuilder<String>(
                                  stream: login.useridValidation,
                                  builder: (context, snapshot) => DataTextField(
                                    errorText: snapshot.error,
                                    hintText: "No Handphone",
                                    textInputAction: TextInputAction.next,
                                    icon: Icons.phone,
                                    onSubmitted: () => FocusScope.of(context).requestFocus(passwordFocusNode),
                                    onChanged: login.userid,
                                    keyboardType: TextInputType.numberWithOptions(signed: true, decimal: true),
                                  ),
                                )
                            ),
                            Container(
                                margin: EdgeInsets.only(top: SizeConfig.heightMultiplier * 2),
                                child: StreamBuilder<String>(
                                  stream: login.passwordValidation,
                                  builder: (context, snapshot) => PasswordTextField(
                                  errorText: snapshot.error,
                                    hintText: "Password",
                                    textInputAction: TextInputAction.done,
                                    onSubmitted: () {
                                      FocusScope.of(context).requestFocus(FocusNode());
                                    },
                                    onChanged: login.password,
                                    focusNode: passwordFocusNode,
                                  ),
                                )
                            ),
                            Container(
                                width: SizeConfig.screenWidth,
                                margin: EdgeInsets.only(top: SizeConfig.heightMultiplier * 2.5),
                                child: GestureDetector(
                                  onTap: () => AppRoutes.push(context, ForgotPasswordPage()),
                                  child: Text(
                                    Strings.titleForgotPass+" ?",
                                    style: AppTheme.styleSubTitlePurpel,
                                    textAlign: TextAlign.right,
                                  ),
                                )
                            ),
                            Container(
                              width: SizeConfig.screenWidth,
                              margin: EdgeInsets.only(top: SizeConfig.heightMultiplier * 5),
                              child: StreamBuilder<bool>(
                                stream: login.submitCheck,
                                builder: (context, snapshot) => AppButton(
                                    onPressed: snapshot.hasData ? () => login.login(context) : null,
                                    text: Strings.signin
                                ),
                              )
                            )
                          ],
                        )
                    )
                ),
                Expanded(
                    flex: 1,
                    child: Container(
                        alignment: Alignment.bottomCenter,
                        margin: EdgeInsets.only(bottom: SizeConfig.heightMultiplier * 2.5),
                        child: Row(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: <Widget>[
                            Text(
                              Strings.dontAccount,
                              style: AppTheme.styleSubTitleBlackSmall,
                              textAlign: TextAlign.right,
                            ),
                            Container(
                                margin: EdgeInsets.only(left: SizeConfig.widthMultiplier * 1),
                                child: InkWell(
                                  onTap: () => AppRoutes.push(context, RegistrationPage()),
                                  child: Text(
                                    Strings.registration,
                                    style: AppTheme.styleSubTitlePurpel,
                                    textAlign: TextAlign.right,
                                  ),
                                )
                            )
                          ],
                        )
                    )
                )
              ],
            ),
          )
      ),
    );
  }
}

Answer 1

似乎你没有任何材料的“背景”，你的错误对话框。试着用脚手架或Material小部件包装你的StreamBuilder。为了设置文本字段的错误，您已经有了相应的errorStreams