How can I receive the message from a QueueStorage of Event Grid (Azure Portal) in a C# Console app?

Question

I'm using Event Grid in a C# console app for send events that are stored in a QueueStorage account in Azure portal. The problem is ¿How can I receive the message stored in a C# console app? for example:

Azure Portal

In the image you can see the topic created and the subscriptions that exist. So, the subscription "queue-sub" have stored all the messages sent from another C# console app. This C# console app implementing the library of eShopContainer of "EventBus"and I'm crating a library to use "EventGrid" with that Interface of "EventBus". For example:

public void Subscribe<T, TH>()
        where T : IntegrationEvent
        where TH : IIntegrationEventHandler<T>
    {
        
    }

This if a fragment code from that implement Interface "IEventBus" and that Interface told me that "I need subscribe for listening the events" but I don´t know how do that.

Here is the git link if you check the whole project that I'm working. https://github.com/Angel1803/EventGridListenerMessage.git

Answer 1

This is how you can write code for receiving messages using IEventBus :

namespace Microsoft.eShopOnContainers.Services.Basket.API.IntegrationEvents.EventHandling
{
    public class ProductPriceChangedIntegrationEventHandler :
        IIntegrationEventHandler<ProductPriceChangedIntegrationEvent>
    {
        private readonly IBasketRepository _repository;

        public ProductPriceChangedIntegrationEventHandler(
            IBasketRepository repository)
        {
            _repository = repository;
        }

        public async Task Handle(ProductPriceChangedIntegrationEvent @event)
        {
            var userIds = await _repository.GetUsers();
            foreach (var id in userIds)
            {
                var basket = await _repository.GetBasket(id);
                await UpdatePriceInBasketItems(@event.ProductId, @event.NewPrice, basket);
            }
        }

        private async Task UpdatePriceInBasketItems(int productId, decimal newPrice,
            CustomerBasket basket)
        {
            var itemsToUpdate = basket?.Items?.Where(x => int.Parse(x.ProductId) ==
                productId).ToList();
            if (itemsToUpdate != null)
            {
                foreach (var item in itemsToUpdate)
                {
                    if(item.UnitPrice != newPrice)
                    {
                        var originalPrice = item.UnitPrice;
                        item.UnitPrice = newPrice;
                        item.OldUnitPrice = originalPrice;
                    }
                }
                await _repository.UpdateBasket(basket);
            }
        }
    }
}

For complete tutorial on IEventBus usage, you can visit Subscribing to events