Flutter - 如果屏幕上未加载数据，则刷新页面

Question

我的 initState 函数中有一个 Future.delayed ，它获取 jwt 缓存并使用它来获取登录用户的详细信息。 initState 函数是：

  @override
  void initState() {
    super.initState();
    Future.delayed(Duration.zero, () async {
      final token = await CacheService().readCache(key: "jwt");
      if (token != null) {
        await Provider.of<ProfileNotifier>(context, listen: false)
            .decodeUserData(
          context: context,
          token: token,
          option: 'home',
        );
      }
    });
  }

现在它确实可以工作，我确实获得了数据，但在第一次运行时没有。我必须热重新加载模拟器，或者导航到另一个页面，然后返回该页面以重建自身并在屏幕上显示数据。我不明白为什么它不显示第一次运行时的数据。

我尝试添加条件来构建方法，以便在数据不存在时再次运行 setState 和 initState 。

  @override
  Widget build(BuildContext context) {
    ProfileModel profile =
        Provider.of<ProfileNotifier>(context, listen: false).profile;
    if (profile.profileName.isEmpty) {
      print('reloading to get data');
      initState();
      setState(() {});
    } ....

它不会运行，因为数据在那里，但不知何故它不会显示在屏幕上，直到刷新页面。我似乎无法弄清楚这里的问题。请帮忙。

编辑：ProfileNotifier 类：

class ProfileNotifier extends ChangeNotifier {
  final ProfileAPI _profileAPI = ProfileAPI();
  final CacheService _cacheService = CacheService();

  ProfileModel _profile = ProfileModel(
    profileImage: "",
    profileName: "",
    profileBio: "",
  );

  AccountModel _account = AccountModel(
    userId: "",
    userEmail: "",
    userPassword: "",
  );

  ProfileModel get profile => _profile;
  AccountModel get account => _account;

  Future decodeUserData({
    required BuildContext context,
    required String token,
    required String option,
  }) async {
    try {
      _profileAPI.decodeUserData(token: token).then((value) async {
        final Map<String, dynamic> parsedData = await jsonDecode(value);
        var userData = parsedData['data'];
        if (userData != null) {
          List<String>? userProfileData = await _cacheService.readProfileCache(
            key: userData['userData']['id'],
          );
          if (userProfileData == null) {
            final isProfileAvailable =
                await Provider.of<ProfileNotifier>(context, listen: false)
                    .getProfile(
              context: context,
              userEmail: userData['userData']['userEmail'],
            );
            if (isProfileAvailable is ProfileModel) {
              _profile = isProfileAvailable;
            } else {
              _account = AccountModel(
                userId: userData['userData']['id'],
                userEmail: userData['userData']['userEmail'],
                userPassword: userData['userData']['userPassword'],
              );
              _profile = ProfileModel(
                profileImage: '',
                profileName: '',
              );
            }
            if (option != 'profileCreation' && isProfileAvailable == false) {
              Navigator.of(context).pushReplacementNamed(ProfileCreationRoute);
            }
          } else {
            _account = AccountModel(
              userId: userData['userData']['id'],
              userEmail: userData['userData']['userEmail'],
              userPassword: userData['userData']['userPassword'],
            );
            _profile = ProfileModel(
              profileName: userProfileData[3],
              profileImage: userProfileData[4],
              profileBio: userProfileData[5],
            );
          }
        } else {
          Navigator.of(context).pushReplacementNamed(AuthRoute);
        }
        notifyListeners();
      });
    } catch (e) {
      debugPrint('account/profileNotifier decode error: ' + e.toString());
    }
  }

  Future getProfile({
    required BuildContext context,
    required String userEmail,
  }) async {
    try {
      var getProfileData = await _profileAPI.getProfile(
        userEmail: userEmail,
      );
      final Map<String, dynamic> parsedProfileData =
          await jsonDecode(getProfileData);
      bool isReceived = parsedProfileData["received"];
      dynamic profileData = parsedProfileData["data"];
      if (isReceived && profileData != 'Fill some info') {
        Map<String, dynamic> data = {
          'id': (profileData['account']['id']).toString(),
          'userEmail': profileData['account']['userEmail'],
          'userPassword': profileData['account']['userPassword'],
          'profile': {
            'profileName': profileData['profileName'],
            'profileImage': profileData['profileImage'],
            'profileBio': profileData['profileBio'],
          }
        };
        AccountModel accountModel = AccountModel.fromJson(
          map: data,
        );
        return accountModel;
      } else {
        return false;
      }
    } catch (e) {
      debugPrint('profileNotifier getProfile error: ' + e.toString());
    }
  }

  Future setProfile({
    required String profileName,
    required String profileImage,
    required String profileBio,
  }) async {
    _profile.profileName = profileName;
    _profile.profileImage = profileImage;
    _profile.profileBio = profileBio;
    await _cacheService.writeProfileCache(
      key: _account.userId,
      value: [
        _account.userId,
        _account.userEmail,
        _account.userPassword as String,
        profileName,
        profileImage,
        profileBio,
      ],
    );
    notifyListeners();
  }
}

我删除了通知程序中的创建配置文件、更新配置文件和配置文件图像上传方法，因为此处不涉及它们。

使用shared_preferences包的CacheService类是：

class CacheService {
  Future<String?> readCache({
    required String key,
  }) async {
    final SharedPreferences sharedPreferences =
        await SharedPreferences.getInstance();
    String? cache = await sharedPreferences.getString(key);
    return cache;
  }

  Future<List<String>?> readProfileCache({
    required String key,
  }) async {
    final SharedPreferences sharedPreferences =
        await SharedPreferences.getInstance();
    List<String>? cachedData = await sharedPreferences.getStringList(key);
    return cachedData;
  }

  Future writeCache({required String key, required String value}) async {
    final SharedPreferences sharedPreferences =
        await SharedPreferences.getInstance();
    await sharedPreferences.setString(key, value);
  }

  Future writeProfileCache(
      {required String key, required List<String> value}) async {
    final SharedPreferences sharedPreferences =
        await SharedPreferences.getInstance();
    await sharedPreferences.setStringList(key, value);
  }

  Future deleteCache({
    required BuildContext context,
    required String key,
  }) async {
    final SharedPreferences sharedPreferences =
        await SharedPreferences.getInstance();
    await sharedPreferences.remove(key).whenComplete(() {
      Navigator.of(context).pushReplacementNamed(AuthRoute);
    });
  }
}

我不确定代码是否完全优化。欢迎任何改进。谢谢。