C# 无法强制转换类型为'；System.Linq.EnumerableQuery`to type'；MongoDB.Driver.Linq.IMongoQueryable`

我有一个具有以下方法句柄的类SendNotificationsToSubscribersCommandHandler，还有一个测试方法GetAllSubscriptionsWithCorrectParamsProductId（），用于检查句柄方法返回的列表是否正确

我发现以下错误：

Message: 
    Test method Grand.Services.Tests.Commands.Handlers.Catalog.SendNotificationsToSubscribersCommandHandlerTest.GetAllSubscriptionsWithCorrectParamsProductId threw exception: 
    System.InvalidCastException: Unable to cast object of type 'System.Linq.EnumerableQuery`1[Grand.Domain.Catalog.BackInStockSubscription]' to type 'MongoDB.Driver.Linq.IMongoQueryable`1[Grand.Domain.Catalog.BackInStockSubscription]'.
  Stack Trace: 
    MongoQueryable.Where[TSource](IMongoQueryable`1 source, Expression`1 predicate)

SendNotificationsToSubscribersCommandHandler

public class SendNotificationsToSubscribersCommandHandler : IRequestHandler<SendNotificationsToSubscribersCommand, IList<BackInStockSubscription>>
    {
        private readonly ICustomerService _customerService;
        private readonly IWorkflowMessageService _workflowMessageService;
        private readonly IRepository<BackInStockSubscription> _backInStockSubscriptionRepository;

        public SendNotificationsToSubscribersCommandHandler(
            ICustomerService customerService,
            IWorkflowMessageService workflowMessageService,
            IRepository<BackInStockSubscription> backInStockSubscriptionRepository)
        {
            _customerService = customerService;
            _workflowMessageService = workflowMessageService;
            _backInStockSubscriptionRepository = backInStockSubscriptionRepository;
        }

        public async Task<IList<BackInStockSubscription>> Handle(SendNotificationsToSubscribersCommand request, CancellationToken cancellationToken)
        {
            if (request.Product == null)
                throw new ArgumentNullException("product");

            int result = 0;

            var query = _backInStockSubscriptionRepository.Table;
            //product
            query = query.Where(biss => biss.ProductId == request.Product.Id);

            //warehouse
            if (!string.IsNullOrEmpty(request.Warehouse))
                query = query.Where(biss => biss.WarehouseId == request.Warehouse);

            //warehouse
            if (!string.IsNullOrEmpty(request.AttributeXml))
                query = query.Where(biss => biss.AttributeXml ==  request.AttributeXml);

            query = query.OrderByDescending(biss => biss.CreatedOnUtc);
            var subscriptions = await query.ToListAsync();
            //var subscriptions = await GetAllSubscriptionsByProductId(request.Product.Id, request.AttributeXml, request.Warehouse);
            foreach (var subscription in subscriptions)
            {
                var customer = await _customerService.GetCustomerById(subscription.CustomerId);
                //ensure that customer is registered (simple and fast way)
                if (customer != null && CommonHelper.IsValidEmail(customer.Email))
                {
                    var customerLanguageId = customer.GetAttributeFromEntity<string>(SystemCustomerAttributeNames.LanguageId, subscription.StoreId);
                    await _workflowMessageService.SendBackInStockNotification(customer, request.Product, subscription, customerLanguageId);
                    result++;
                }
            }

            return subscriptions;

        }
}

更新

调试应用程序时，属性

\u backInStockSubscriptionRepository.Table

具有

Expression.Value={aggregate（[]）}

如果我调试模拟对象的测试方法属性表有Expression.Value和Value=

System.Collections.Generic.List

以及我的两个对象

非常感谢您的帮助

请查看以下内容：

试着这样做：

_mongoQueryableMock = new Mock<IMongoQueryable<BackInStockSubscription>>();
_mongoQueryableMock.As<IEnumerable<BackInStockSubscription>>();
...

\u mongoQueryableMock=new Mock（）；
_mongoQueryableMock.As（）；
...

看看这里：

试着这样做：

_mongoQueryableMock = new Mock<IMongoQueryable<BackInStockSubscription>>();
_mongoQueryableMock.As<IEnumerable<BackInStockSubscription>>();
...

\u mongoQueryableMock=new Mock（）；
_mongoQueryableMock.As（）；
...

哪一行导致异常？方法句柄，行query=query.Where（biss=>biss.ProductId==ProductId）；哪一行导致了异常？方法句柄，行query=query.Where（biss=>biss.ProductId==ProductId）<代码>\u mongoQueryableMock.As（）相同的错误。我很确定这与此有关，但我没有解决方案。尝试创建一个假的或存根，而不是使用Moq。只是为了测试。我想我已经找到了原因，但如何解决我发现很难回答。我更新了我的问题。你能检查一下吗。谢谢您您可以尝试发布您的

IRepository.Table

的实现。但我看到其他人在嘲笑IMongoQueryable时遇到了问题。我也面临着同样的问题。。你能解决它吗？

\u mongoQueryableMock.As（）相同的错误。我很确定这与此有关，但我没有解决方案。尝试创建一个假的或存根，而不是使用Moq。只是为了测试。我想我已经找到了原因，但如何解决我发现很难回答。我更新了我的问题。你能检查一下吗。谢谢您您可以尝试发布您的
IRepository.Table
的实现。但我看到其他人在嘲笑IMongoQueryable时遇到了问题。我也面临着同样的问题。。你能解决它吗？
_mongoQueryableMock = new Mock<IMongoQueryable<BackInStockSubscription>>();
_mongoQueryableMock.As<IEnumerable<BackInStockSubscription>>();
...