共享偏好：值未在实时或立即更新

Question

我正在尝试实现用户在一个屏幕上提供输入的功能，并且数据在本地存储（共享的首选项），并且一旦用户返回另一个屏幕或弹出，则应立即将数据从该屏幕上更新到该屏幕。上一个屏幕。当前发生的事情是，仅当我导航到另一个屏幕并导航回该屏幕时，数据才会更新。

SharedPreferences
import 'package:shared_preferences/shared_preferences.dart';


class UserSimplePreferences {
  static late SharedPreferences _preferences;
  static const _name = 'name';
  static const _age = 'age';
  static const _gender = 'gender';
  static const _church = 'church';
  static const _churchCity = 'churchCity';
  static const _churchState = 'churchState';


  static Future init() async =>
      _preferences = await SharedPreferences.getInstance();

  static Future setName(String name) async =>
      await _preferences.setString(_name, name);

  static String? getName() => _preferences.getString(_name);

  static Future setAge(String age) async =>
      await _preferences.setString(_age, age);

  static String? getAge() => _preferences.getString(_age);

  static Future setGender(String gender) async =>
      await _preferences.setString(_gender, gender);

  static String? getGender() => _preferences.getString(_gender);

  static Future setChurch(String church) async =>
      await _preferences.setString(_gender, church);

  static String? getChurch() => _preferences.getString(_church);


  static Future setChurchCity(String churchCity) async =>
      await _preferences.setString(_gender, churchCity);

  static String? getChurchCity() => _preferences.getString(_churchCity);


  static Future setChurchState(String churchState) async =>
      await _preferences.setString(_gender, churchState);

  static String? getChurchState() => _preferences.getString(_churchState);


}


Register(Here the data should be updated)

class Register extends StatefulWidget {


  @override
  _RegisterState createState() => _RegisterState();
}

class _RegisterState extends State<Register> {
  late String? name = UserSimplePreferences.getName();

 // final user = UserSimplePreferences.getUser();

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
     }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
    body:Container(
        child:  Column(
          children: [
            Card(
              child: Text(name??''),
            ),
            Card(
              child: Text(name??''),
            ),
            Card(
              child: Text(name??''),
            )
          ],

       )
      ),
      floatingActionButton: FloatingActionButton(
        backgroundColor: Colors.indigo[900],
        onPressed: () {
          Navigator.push(
            context,
            MaterialPageRoute(builder: (_) {
              return AddUser(idUser: '',);
            }),
          );
        },
        child: Icon(Icons.add, color: Colors.white),
      ),
    );

  }
}



AddUser(where user provides input)
class AddUser extends StatefulWidget {

  final String? idUser;


  const AddUser({required this.idUser});

  @override
  _AddUserState createState() => _AddUserState();

}

class _AddUserState extends State<AddUser> {

  final formKey = GlobalKey<FormState>();
  String name = '';
 String age = '';
 String gender= '';
 String church= '';
 String  churchCity= '';
  String churchState= '';

  @override
  void initState() {
    super.initState();

    // name = UserSimplePreferences.getName() ?? '';
    // age = UserSimplePreferences.getAge() ?? '';
    // gender = UserSimplePreferences.getGender() ?? '';
    // church = UserSimplePreferences.getChurch() ?? '';
    //  churchCity = UserSimplePreferences.getChurchCity() ?? '';
    // churchState = UserSimplePreferences.getChurchState() ?? '';

  }

  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(
      automaticallyImplyLeading: false,
      title : Text('Please Enter Your Details',textAlign: TextAlign.center,)),

    body: SafeArea(
          child: ListView(
        padding: EdgeInsets.all(16),
        children: [

          buildName(),
          const SizedBox(height: 12),
          buildAge(),
          const SizedBox(height: 12),
          buildGender(),
          const SizedBox(height: 12),
          buildChurch(),
          const SizedBox(height: 12),
          buildChurchCity(),
          const SizedBox(height: 12),
          buildChurchState(),
          const SizedBox(height: 12),

          buildButton(),
        ],
      ),
    ),
  );

  Widget buildName() =>

    buildTitle(
    title: 'Name',
    child: TextFormField(
      initialValue: name,
      decoration: InputDecoration(
        border: OutlineInputBorder(),
        hintText: 'Your Name',
      ),
      onChanged: (name) => setState(() => this.name = name),
    ),
  );

  Widget buildAge() => buildTitle(
    title: 'Age',
    child: TextFormField(
      initialValue: age,
      decoration: InputDecoration(
        border: OutlineInputBorder(),
        hintText: 'Your Age',
      ),
      onChanged: (age) => setState(() => this.age = age),
    ),
  );
  Widget buildGender() => buildTitle(
    title: 'Gender',
    child: TextFormField(
      initialValue: gender,
      decoration: InputDecoration(
        border: OutlineInputBorder(),
        hintText: 'Your gender(M/F)',
      ),
      onChanged: (gender) => setState(() => this.gender = gender),
    ),
  );
  Widget buildChurch() => buildTitle(
    title: 'Church',
    child: TextFormField(
      initialValue: church,
      decoration: InputDecoration(
        border: OutlineInputBorder(),
        hintText: 'Your church',
      ),
      onChanged: (church) => setState(() => this.church = church),
    ),
  );
  Widget buildChurchCity() => buildTitle(
    title: 'Church City',
    child: TextFormField(
      initialValue: churchCity,
      decoration: InputDecoration(
        border: OutlineInputBorder(),
        hintText: 'Your Church City',
      ),
      onChanged: (churchCity) => setState(() => this.churchCity = churchCity),
    ),
  );
  Widget buildChurchState() => buildTitle(
    title: 'Church State',
    child: TextFormField(
      initialValue: churchState,
      decoration: InputDecoration(
        border: OutlineInputBorder(),
        hintText: 'Your Church State',
      ),
      onChanged: (churchState) => setState(() => this.churchState = churchState),
    ),
  );


  Widget buildButton() => ButtonWidget(
      text: 'Save',
      onClicked: () async {

        await UserSimplePreferences.setName(name);
        await UserSimplePreferences.setAge(age);
        await UserSimplePreferences.setGender(gender);
        await UserSimplePreferences.setChurch(church);
        await UserSimplePreferences.setChurchCity(churchCity);
        await UserSimplePreferences.setChurchState(churchState);
             Navigator.pop(context);
      });

  Widget buildTitle({
    required String title,
    required Widget child,
  }) =>
      Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Text(
            title,
            style: TextStyle(fontWeight: FontWeight.bold, fontSize: 18),
          ),
          const SizedBox(height: 8),
          child,
        ],
      );
}

Answer 1

您首次构建视图，然后加载数据。在力setstate上没有视图交互，因此在此视图上没有任何更改。您现在可以做什么？
您有两种方法：

1. 运行setState从sharone_pref
2. 使用funerbuilder 以后呈现另一个小部件，然后加载数据后，
   我建议第二选项