Question

请在下面查看我的第一个永久订阅：

 namespace PersistentSubscription
    {
        internal class Program
        {
            private static void Main()
            {
                var subscription = new PersistentSubscriptionClient();
                subscription.Start();
            }
        }

        public class PersistentSubscriptionClient
        {
            private IEventStoreConnection _conn;
            private const string STREAM = "$ce-customer";
            private const string GROUP = "a_test_group";
            private const int DEFAULTPORT = 1113;
            private static readonly UserCredentials User = new UserCredentials("admin", "changeit");
            private EventStorePersistentSubscriptionBase _subscription;

            public void Start()
            {
                var settings = ConnectionSettings.Create(); 

                using (_conn = EventStoreConnection.Create(settings, new IPEndPoint(IPAddress.Loopback, DEFAULTPORT)))
                {
                    _conn.ConnectAsync().Wait();

                    CreateSubscription(); 
                    ConnectToSubscription();

                    Console.WriteLine("waiting for events. press enter to exit");
                    Console.ReadLine();
                }
            }

            private void ConnectToSubscription()
            {
                var bufferSize = 10;
                var autoAck = true;

                Action<EventStorePersistentSubscriptionBase, ResolvedEvent> eventAppeared = EventAppeared; 
                _subscription = _conn.ConnectToPersistentSubscription(STREAM, GROUP, eventAppeared, SubscriptionDropped, User, bufferSize, autoAck);
            }

            private void SubscriptionDropped(EventStorePersistentSubscriptionBase eventStorePersistentSubscriptionBase,
                SubscriptionDropReason subscriptionDropReason, Exception ex)
            {
                ConnectToSubscription();
            }

            private static void EventAppeared(EventStorePersistentSubscriptionBase eventStorePersistentSubscriptionBase,
                ResolvedEvent resolvedEvent)
            {
                MemoryStream stream = new MemoryStream(resolvedEvent.Event.Data);
                IFormatter formatter = new BinaryFormatter();
                stream.Seek(0, SeekOrigin.Begin);
                try
                {
                    CustomerCreated customerCreated = (CustomerCreated)formatter.Deserialize(stream); 
                    Console.WriteLine(customerCreated);
                }
                catch (Exception e)
                {
                    var test = "test";
                }

            }

            private void CreateSubscription()
            {
                PersistentSubscriptionSettings settings = PersistentSubscriptionSettings.Create()
                    .DoNotResolveLinkTos()
                    .StartFromCurrent();

                try
                {
                    _conn.CreatePersistentSubscriptionAsync(STREAM, GROUP, settings, User).Wait();
                }
                catch (AggregateException ex)
                {
                    if (ex.InnerException.GetType() != typeof(InvalidOperationException)
                        && ex.InnerException?.Message != $"Subscription group {GROUP} on stream {STREAM} already exists")
                    {
                        throw;
                    }
                }
            }
        }
    }

和下面的第一个客户

using System;
using System.IO;
using System.Net;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text;
using EventStore.ClientAPI;

namespace WritingEvents
{
    class Program
    {
        static void Main(string[] args)
        {
            const int DEFAULTPORT = 1113;
            var settings = ConnectionSettings.Create();
            using (var conn = EventStoreConnection.Create(settings, new IPEndPoint(IPAddress.Loopback, DEFAULTPORT)))
            {
                conn.ConnectAsync().Wait();
                CustomerCreated c1 = new CustomerCreated { Id = Guid.NewGuid(), Name = "Maria" };
                EventData customerCreated1 = GetEventDataFor(c1);
                conn.AppendToStreamAsync("customer-100", ExpectedVersion.Any, customerCreated1).Wait();
            }
        }

        private static EventData GetEventDataFor(CustomerCreated customerCreated)
        {
            IFormatter formatter = new BinaryFormatter();
            MemoryStream stream = new MemoryStream();
            formatter.Serialize(stream, customerCreated);
            byte[] customerCreatedEventByteArray = stream.ToArray();



            return new EventData(
                Guid.NewGuid(),
                "eventType",
                true,
                customerCreatedEventByteArray,
                null
                );
        }
    }

    [Serializable]
    public class CustomerCreated
    {
        public Guid Id { get; set; }
        public string Name { get; set; }
    }
}

我先运行服务器，然后运行客户端。在服务器端反序列化CustomerCreated事件时，看到一个错误。错误为：“在解析完成之前遇到流尾”。

如果我更改此行：

private const string STREAM = "$ce-customer";

对此：

private const string STREAM = "customer-100";

然后反序列化可以在服务器端正常工作。

我如何处理所有客户事件-不只是客户100？

启动事件存储时，我有--run-projections=all。我还启用了所有预测：

Answer 1

这个问题对我有帮助：Using the Event Store Client API (.NET), how to I write to a stream and link one event to another?

我只需更改此内容即可

PersistentSubscriptionSettings settings = PersistentSubscriptionSettings.Create()
                .DoNotResolveLinkTos() //Specifically this line
                .StartFromCurrent();

对此：

PersistentSubscriptionSettings settings = PersistentSubscriptionSettings.Create()
                .ResolveLinkTos() //Specifically this line
                .StartFromCurrent();

DoNotResolveLinkTos获取到原始事件的链接，而ResolveLinkTos获取实际事件本身。因此，我试图反序列化导致异常的链接对象。

处理所有事件以汇总

1 个答案: