Workmanager 和 get_it 用于通知目的

Question

我们正在使用 get_it^7.2.0 和 workmanager^0.4.1 进行依赖注入 (get_it) 和后台任务 (workmanager) 的调度。

想要在workmanager.executeTask()函数中注册类后出现问题。

final sl = GetIt.instance;
...
sl.registerLazySingleton<BackgroundRunner>(() => BackgroundRunnerImpl(tasks: sl()));
...

注册后，这一切都发生在异步函数中，我想要通过调用对象：

void initializeBackgroundTask() {
     Workmanager().initialize(callbackDispatcher, isInDebugMode: false);
     Workmanager().registerPeriodicTask("1", "simplePeriodicTask",
         frequency: Duration(minutes: 45), initialDelay: Duration(seconds: 10));
}

void callbackDispatcher() {
     BackgroundRunner backgroundRunner = di.sl.get<BackgroundRunner>();
     Workmanager().executeTask((task, inputData) {
     // Does Workload
     backgroundRunner.runBackground();
     return Future.value(true);
     });
}

每当 Workmanager 调用 callbackDispatcher 时，我都会收到以下异常。

E/flutter ( 6388): [ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: 'package:get_it/get_it_impl.dart': Failed assertion: line 372 pos 7: 'instanceFactory != null': Object/factory with type BackgroundRunner is not registered inside GetIt. E/flutter ( 6388): (Did you accidentally do GetIt sl=GetIt.instance(); instead of GetIt sl=GetIt.instance; E/flutter ( 6388): Did you forget to register it?)

我在哪里犯错了？

Answer 1

您必须在后台重新注册它们才能使用它们！

void callbackDispatcher() {
  Workmanager().executeTask((task, inputData) async {
    // Does Workload
    await Firebase.initializeApp();
    await di.init();
    BackgroundRunner backgroundRunner = di.sl.get<BackgroundRunner>();
    backgroundRunner.runBackground();
    return Future.value(true);
  });