[英]Flutter dependency injenction with shared preferences
晚上好,我正在嘗試將依賴注入與共享首選項插件一起使用,但是一旦我生成代碼,我就會收到一個不相關 Bloc 的錯誤。 我用
我的目標是將 SharedPreferences 注入 class 以處理本地操作,它看起來像這樣:
class LocalSharedPreferences {
final SharedPreferences _preferences;
LocalSharedPreferences(this._preferences);
...
}
為了正確注入 SharedPreferences,我遵循了它的官方文檔( https://pub.dev/packages/injectable#registering-asynchronous-injectables ),因此我注入第 3 方模塊的代碼如下所示:
@module
abstract class RegisterModule {
@preResolve
Future<SharedPreferences> get prefs => SharedPreferences.getInstance();
}
我在 StackOverflow 上關注了這個問題,但它沒有用。 我的錯誤如下:
The following assertion was thrown building SignInForm(dependencies: [MediaQuery]):
Object/factory with type SignInFormBloc is not registered inside GetIt.
(Did you accidentally do GetIt sl=GetIt.instance(); instead of GetIt sl=GetIt.instance;
Did you forget to register it?)
'package:get_it/get_it_impl.dart':
Failed assertion: line 298 pos 9: 'instanceFactory != null'
自動生成的注入代碼如下所示:
Future<GetIt> $initGetIt(
GetIt get, {
String environment,
EnvironmentFilter environmentFilter,
}) async {
final gh = GetItHelper(get, environment, environmentFilter);
final registerModule = _$RegisterModule();
gh.factory<DatosBauServerApiHelper>(() => DatosBauServerApiHelper());
gh.factory<DatosBauServerAuth>(
() => DatosBauServerAuth(get<DatosBauServerApiHelper>()));
gh.lazySingleton<IAuthFacade>(
() => DatosBauServerAuthFacade(get<DatosBauServerAuth>()));
final sharedPreferences = await registerModule.prefs;
gh.factory<SharedPreferences>(() => sharedPreferences);
gh.factory<SignInFormBloc>(() => SignInFormBloc(get<IAuthFacade>()));
return get;
}
class _$RegisterModule extends RegisterModule {}
Package得到它
LocalSharedPreferences class
abstract class LocalSharedPreferences {
// ...
}
LocalSharedPreferencesImpl class
class LocalSharedPreferencesImpl extends LocalSharedPreferences {
// ...
// Use your globalSharedPrefs variable here
}
另一個dart文件
GetIt locator = GetIt.instance;
setupServicesLocator() {
locator.registerLazySingleton<LocalSharedPreferences>(() => LocalSharedPreferencesImpl());
}
您的 main.dart 文件
SharedPreferences globalSharedPrefs;
void main() async {
/* ENSURE ASYNC WILL NOT GENERATE RUNTIME ERROR */
WidgetsFlutterBinding.ensureInitialized();
/* GLOBAL SERVICES */
setupServicesLocator();
/* Initialize your globalSharedPreferences variable here */
globalSharedPrefs = await SharedPreferences.getInstance();
}
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