abp.io Hangfire 无法访问已释放的上下文实例

Question

我正在尝试在应用程序启动时设置 Hangfire 循环作业，但如果我尝试在作业中使用注入的 IRepository；它给了我这个错误

System.ObjectDisposedException
Cannot access a disposed context instance. A common cause of this error is disposing a context instance that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling 'Dispose' on the context instance, or wrapping it in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances. Object name: 'TMSDbContext'.

System.ObjectDisposedException: Cannot access a disposed context instance. A common cause of this error is disposing a context instance that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling 'Dispose' on the context instance, or wrapping it in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.
Object name: 'TMSDbContext'.
   at Microsoft.EntityFrameworkCore.DbContext.CheckDisposed()
   at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
   at Microsoft.EntityFrameworkCore.DbContext.get_Model()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityType()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.CheckState()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.get_EntityQueryable()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.System.Linq.IQueryable.get_Provider()
   at Volo.Abp.EntityFrameworkCore.EfCoreAsyncQueryableProvider.CanExecute[T](IQueryable`1 queryable)
   at Volo.Abp.Linq.AsyncQueryableExecuter.<>c__DisplayClass4_0`1.<FindProvider>b__0(IAsyncQueryableProvider p)
   at System.Linq.Enumerable.TryGetFirst[TSource](IEnumerable`1 source, Func`2 predicate, Boolean& found)
   at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)
   at Volo.Abp.Linq.AsyncQueryableExecuter.FindProvider[T](IQueryable`1 queryable)
   at Volo.Abp.Linq.AsyncQueryableExecuter.ToListAsync[T](IQueryable`1 queryable, CancellationToken cancellationToken)
   at Volo.Abp.Domain.Repositories.RepositoryAsyncExtensions.ToListAsync[T](IReadOnlyRepository`1 repository, CancellationToken cancellationToken)
   at MB.TMS.Application.BackgroundServices.Hangfire.BookingAlarmFunction() in C:\Users\ahmad\source\repos\TMS-Abp4\aspnet-core\src\MB.TMS.Application\BackgroundServices\Hangfire.cs:line 53
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()

我已经完全按照 ABP 文档中的描述注册了 Hangfire，并且它从事基本的重复性工作，例如

RecurringJob.AddOrUpdate(
    () => Console.WriteLine("Recurring!"),
    Cron.Daily);

我已在 ApplicationModule 中将我的服务注册为 Scoped 服务

 public override void ConfigureServices(ServiceConfigurationContext context)
        {
            Configure<AbpAutoMapperOptions>(options =>
            {
                options.AddMaps<TMSApplicationModule>();
            });


            context.Services.AddScoped<IHangfire, Hangfire>();
        }

而我的工作方法只是尝试使用注入的存储库进行查询。

    public class Hangfire : IHangfire
    {
    
        private readonly IRepository<Booking, int> _bookingsRepository;
        private readonly IBookingSignalR _bookingSignalR;
        private readonly IObjectMapper _objectMapper;

        public Hangfire(
            IRepository<Booking, int> bookingsRepository,
            IBookingSignalR bookingSignalR,
            IObjectMapper objectMapper)
        {
            _bookingsRepository = bookingsRepository;
            _bookingSignalR = bookingSignalR;
            _objectMapper = objectMapper;
        }
    
        public void BookingAlarmRecurringJob()
        {
        RecurringJob.AddOrUpdate(
        () => BookingAlarmFunction(),
        Cron.Minutely());
        }

        [UnitOfWork]
        public virtual async Task BookingAlarmFunction()
        {
            

            var bookings = await _bookingsRepository
                                        .ToListAsync();

            bookings.ForEach(async booking =>
            {
                if (IsPlanningAlramActive(booking))
                {
                    booking.IsPlanningAlarmActive = true;
                    await SendSignalR(booking);

                }

                else if (IsPickupAlarmActive(booking))
                {
                    booking.IsPlanningAlarmActive = false;
                    booking.IsPickupAlarmActive = true;
                    await SendSignalR(booking);
                }
            });

        }
    }
}

Answer 1

在 BookingAlarmFunction 方法中手动创建一个 uow 就可以了

public class Hangfire : IHangfire
    {
        private readonly IUnitOfWorkManager _unitOfWorkManager;

        public Hangfire(
            IUnitOfWorkManager unitOfWorkManager)
        {
            _unitOfWorkManager = unitOfWorkManager;
        }

        public virtual async Task BookingAlarmFunction()
        {
            using (var uow = _unitOfWorkManager.Begin(requiresNew: true, isTransactional: true))
            {
                var bookings = await _bookingsRepository
                                       .ToListAsync();

                await uow.CompleteAsync();
            }

        }
}