如何解决Flutter Dart：BLoC模式可在两个不同的StreamBuilder中更新数据
编辑：张贴了我的登录表格。
在“使用电子邮件和密码登录/注册”屏幕上，我有一个Scaffold和一个AppBar，一个body: List<Widget> FormColumn，后者在一个单独的文件中并被导入。
在我的表单文件中，我让StreamBuilder监听包含数据的块和一个FlatButton，该StreamBuilder将表单逻辑从登录逻辑切换为注册逻辑，请参见如下图所示，我在脚手架上做了第二个class SignInDialog extends StatefulWidget {
final EmailPwSignBloc bloc;
const SignInDialog({Key key,@required this.bloc}) : super(key: key);
// this is my static function
// it builds the screen
// used 'makeScreenWithbloc' because create is already
// used in this file
static Widget makeScreenWithbloc(BuildContext context){
AuthService authService = Provider.of<AuthService>(context);
return Provider<EmailPwSignBloc>(
create: (context) => EmailPwSignBloc(authService: authService),dispose: (context,bloc) => bloc.dispose(),child: Consumer<EmailPwSignBloc>(builder: (context,blocFromProvider,_) => SignInDialog(bloc: blocFromProvider,)),);
}
static void create(BuildContext context){
// ADDING STATE TO THE APPBAR
}
@override
_SignInDialogState createState() => _SignInDialogState();
}
class _SignInDialogState extends State<SignInDialog> {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: StreamBuilder<EmailSignInModel>(
stream: widget.bloc.getEmailSignInModel,initialData: EmailSignInModel(),builder: (context,snapshot) {
final EmailSignInModel data = snapshot.data;
return Text(data.appBarText);
}
),// TODO: Bool SignIn/Register
centerTitle: true),body: Container(
child: SingleChildScrollView(
child: Padding(
padding: EdgeInsets.all(15),child: Card(
child: SignInFormBlocCompatible.create(context),)
),);
}
}
，如下所示：
class SignInFormBlocCompatible extends StatefulWidget
with EmailAndPasswordStringValidator {
final EmailPwSignBloc bloc;
SignInFormBlocCompatible({
Key key,@required this.bloc,}) : super(key: key);
static Widget create(context) {
AuthService authService = Provider.of<AuthService>(context);
return Provider<EmailPwSignBloc>(
create: (context) => EmailPwSignBloc(authService: authService),child: Consumer<EmailPwSignBloc>(
builder: (context,bloc,_) => SignInFormBlocCompatible(bloc: bloc),),);
}
@override
_SignInFormState createState() => _SignInFormState();
}
class _SignInFormState extends State<SignInFormBlocCompatible> {
@override
Widget build(BuildContext context) {
return StreamBuilder<EmailSignInModel>(
stream: widget.bloc.getEmailSignInModel,snapshot) {
final EmailSignInModel model = snapshot.data;
return Padding(
padding: const EdgeInsets.fromLTRB(15,30,15,15),child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,mainAxisSize: MainAxisSize.min,children: _listOfFormElements(model),);
}
);
}
static TextEditingController _emailController = TextEditingController();
static TextEditingController _passwordController = TextEditingController();
// creating the submit function
Future<void> _submit(EmailSignInModel model) async {
// if it is on sign in use sign in function ELSE use register function
try {
await widget.bloc.submit();
Navigator.pop(context);
} on PlatformException catch (e) {
print(e.toString());
}
}
List<Widget> _listOfFormElements(EmailSignInModel model) {
Login_or_reg defaultType = model.loginOrReg;
// validating button text
var validatingButtonText =
defaultType == Login_or_reg.signIn ? 'Log In' : 'Create Account';
// switch between login or register button
var switchLogInOrRegisterText = defaultType == Login_or_reg.signIn
? "Don't have an account? Register"
: 'Have an account? Log in';
// this function is used to switch between function
// when switching it clears the fields of text
void _signInOrReg(model) {
model.loginOrReg == Login_or_reg.signIn ? widget.bloc.updateModel(email: '',password: '',submitted: false,appBarText: 'Register',loginOrReg: Login_or_reg.register): widget.bloc.updateModel(email: '',appBarText: 'Log In',loginOrReg: Login_or_reg.signIn);
_emailController.clear();
_passwordController.clear();
}
return [
// email
TextFormField(
autocorrect: false,controller: _emailController,onChanged: (value) => widget.bloc.updateModel(email: value),decoration: InputDecoration(
enabled: model.enabled == true,hintText: 'example@example.com',labelText: 'eMail',SizedBox(height: 10),// password
TextFormField(
autocorrect: false,onChanged: (value) => widget.bloc.updateModel(password: value),controller: _passwordController,obscureText: true,onEditingComplete: () => _submit(model),decoration: InputDecoration(
hintText: 'Your password here',labelText: 'Password',SizedBox(height: 20),// my sign in/register button
CustomFlatButton(
text: validatingButtonText,color: Colors.indigo,textColor: Colors.white,// my bool signin/register button
CustomFlatButton(
text: switchLogInOrRegisterText,color: Color(0xff),callback: model.enabled ? () => _signInOrReg(model) : null,textColor: Colors.indigo,)
];
}
}
为了能够更新 appBar标题。
这是登录表单：
class EmailPwSignBloc {
final AuthService authService;
EmailPwSignBloc({@required this.authService});
StreamController<EmailSignInModel> _streamController =
StreamController<EmailSignInModel>();
// GETTER
Stream<EmailSignInModel> get getEmailSignInModel => _streamController.stream;
// SETTER
set _setEmailSignInModel(EmailSignInModel model) =>
_streamController.sink.add(model);
EmailSignInModel _modelInstance = EmailSignInModel();
void dispose() {
_streamController.close();
}
// changing model values
void updateModel({
String email,String password,Login_or_reg loginOrReg,String appBarText,bool submitted,bool enabled,}) {
// updating model
_modelInstance = _modelInstance.copyWith(
email: email,password: password,appBarText: appBarText,loginOrReg: loginOrReg,submitted: submitted,enabled: enabled,);
_setEmailSignInModel = _modelInstance;
}
Future<void> submit() async {
updateModel(submitted: true,enabled: false);
// if it is on sign in use sign in function ELSE use register function
try {
if (_modelInstance.loginOrReg == Login_or_reg.signIn) {
await authService.signInWithEmail(
_modelInstance.email,_modelInstance.password);
} else {
await authService.registerWithEmail(
_modelInstance.email,_modelInstance.password);
}
} catch (e) {
print('Error occurred and rethrown.');
print(e.toString());
rethrow;
} finally {
updateModel(enabled: true);
}
}
这是我在集团中的登录名
enum Login_or_reg {
signIn,register,}
class EmailSignInModel {
final String email;
final String password;
final String appBarText;
final Login_or_reg loginOrReg;
final bool submitted;
final bool enabled;
EmailSignInModel({
this.email = '',this.password = '',this.appBarText = 'Log In',// TODO: change default appBar text
this.loginOrReg = Login_or_reg.signIn,this.submitted = false,this.enabled = true,});
EmailSignInModel copyWith({
String email,}) {
// TODO: Take off leText & print
String leText;
leText = appBarText ?? this.appBarText;
print(leText);
return EmailSignInModel(
email: email ?? this.email,password: password ?? this.password,appBarText: appBarText ?? this.appBarText,enabled: enabled ?? this.enabled,submitted: submitted ?? this.submitted,loginOrReg: loginOrReg ?? this.loginOrReg,);
}
}
这是我的登录模型：
arm-linux-gnueabihf-as -o testas.o testas.s
arm-linux-gnueabihf-gcc -o testas testas.o
问题：除AppBar标题外，其他所有东西都正常运行。我在执行中做错了吗？
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