Try to get the service instance using the serviceProvider.GetServices method. (#356)

src/DotNetCore.CAP/CAP.ServiceCollectionExtensions.cs

@@ -21,6 +21,7 @@ namespace Microsoft.Extensions.DependencyInjection
     /// </summary>
     public static class ServiceCollectionExtensions
     {
+        internal static IServiceCollection ServiceCollection;
         /// <summary>
         /// Adds and configures the consistence services for the consistency.
         /// </summary>
@@ -34,10 +35,9 @@ namespace Microsoft.Extensions.DependencyInjection
                 throw new ArgumentNullException(nameof(setupAction));
             }
 
-            services.TryAddSingleton<CapMarkerService>();
+            ServiceCollection = services;
 
-            //Consumer service
-            AddSubscribeServices(services);
+            services.TryAddSingleton<CapMarkerService>();
 
             //Serializer and model binder
             services.TryAddSingleton<IContentSerializer, JsonContentSerializer>();
@@ -80,24 +80,5 @@ namespace Microsoft.Extensions.DependencyInjection
 
             return new CapBuilder(services);
         }
-
-        private static void AddSubscribeServices(IServiceCollection services)
-        {
-            var consumerListenerServices = new List<KeyValuePair<Type, Type>>();
-            foreach (var rejectedServices in services)
-            {
-                if (rejectedServices.ImplementationType != null
-                    && typeof(ICapSubscribe).IsAssignableFrom(rejectedServices.ImplementationType))
-                {
-                    consumerListenerServices.Add(new KeyValuePair<Type, Type>(typeof(ICapSubscribe),
-                        rejectedServices.ImplementationType));
-                }
-            }
-
-            foreach (var service in consumerListenerServices)
-            {
-                services.TryAddEnumerable(ServiceDescriptor.Transient(service.Key, service.Value));
-            }
-        }
     }
 }
\ No newline at end of file

src/DotNetCore.CAP/ConsumerExecutorDescriptor.cs

@@ -11,6 +11,8 @@ namespace DotNetCore.CAP
     /// </summary>
     public class ConsumerExecutorDescriptor
     {
+        public TypeInfo ServiceTypeInfo { get; set; }
+
         public MethodInfo MethodInfo { get; set; }
 
         public TypeInfo ImplTypeInfo { get; set; }

src/DotNetCore.CAP/IConsumerServiceSelector.Default.cs

@@ -76,23 +76,21 @@ namespace DotNetCore.CAP
         {
             var executorDescriptorList = new List<ConsumerExecutorDescriptor>();
 
-            using (var scoped = provider.CreateScope())
-            {
-                var scopedProvider = scoped.ServiceProvider;
-                var consumerServices = scopedProvider.GetServices<ICapSubscribe>();
-                foreach (var service in consumerServices)
-                {
-                    var typeInfo = service.GetType().GetTypeInfo();
-                    if (!typeof(ICapSubscribe).GetTypeInfo().IsAssignableFrom(typeInfo))
-                    {
-                        continue;
-                    }
-
-                    executorDescriptorList.AddRange(GetTopicAttributesDescription(typeInfo));
+            var capSubscribeTypeInfo = typeof(ICapSubscribe).GetTypeInfo();
+
+            foreach (var service in ServiceCollectionExtensions.ServiceCollection.Where(o => o.ImplementationType != null && o.ServiceType != null))
+            {
+                var typeInfo = service.ImplementationType.GetTypeInfo();
+                if (!capSubscribeTypeInfo.IsAssignableFrom(typeInfo))
+                {
+                    continue;
                 }
-
-                return executorDescriptorList;
-            }
+                var serviceTypeInfo = service.ServiceType.GetTypeInfo();
+
+                executorDescriptorList.AddRange(GetTopicAttributesDescription(typeInfo, serviceTypeInfo));
+            }
+
+            return executorDescriptorList;
         }
 
         protected virtual IEnumerable<ConsumerExecutorDescriptor> FindConsumersFromControllerTypes()
@@ -112,7 +110,7 @@ namespace DotNetCore.CAP
             return executorDescriptorList;
         }
 
-        protected IEnumerable<ConsumerExecutorDescriptor> GetTopicAttributesDescription(TypeInfo typeInfo)
+        protected IEnumerable<ConsumerExecutorDescriptor> GetTopicAttributesDescription(TypeInfo typeInfo, TypeInfo serviceTypeInfo = null)
         {
             foreach (var method in typeInfo.DeclaredMethods)
             {
@@ -135,7 +133,7 @@ namespace DotNetCore.CAP
                         attr.Group = attr.Group + "." + _capOptions.Version;
                     }
 
-                    yield return InitDescriptor(attr, method, typeInfo);
+                    yield return InitDescriptor(attr, method, typeInfo, serviceTypeInfo);
                 }
             }
         }
@@ -143,13 +141,15 @@ namespace DotNetCore.CAP
         private static ConsumerExecutorDescriptor InitDescriptor(
             TopicAttribute attr,
             MethodInfo methodInfo,
-            TypeInfo implType)
+            TypeInfo implType,
+            TypeInfo serviceTypeInfo)
         {
             var descriptor = new ConsumerExecutorDescriptor
             {
                 Attribute = attr,
                 MethodInfo = methodInfo,
-                ImplTypeInfo = implType
+                ImplTypeInfo = implType,
+                ServiceTypeInfo = serviceTypeInfo
             };
 
             return descriptor;

src/DotNetCore.CAP/Internal/IConsumerInvoker.Default.cs

@@ -2,6 +2,8 @@
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
 using System;
+using System.Linq;
+using System.Reflection;
 using System.Threading.Tasks;
 using DotNetCore.CAP.Abstractions;
 using Microsoft.Extensions.DependencyInjection;
@@ -38,9 +40,20 @@ namespace DotNetCore.CAP.Internal
 
             using (var scope = _serviceProvider.CreateScope())
             {
-                var provider = scope.ServiceProvider;
+                var provider = scope.ServiceProvider;
                 var serviceType = context.ConsumerDescriptor.ImplTypeInfo.AsType();
-                var obj = ActivatorUtilities.GetServiceOrCreateInstance(provider, serviceType);
+                object obj = null;
+
+                if (context.ConsumerDescriptor.ServiceTypeInfo != null)
+                {
+                    obj = provider.GetServices(context.ConsumerDescriptor.ServiceTypeInfo.AsType())
+                        .FirstOrDefault(o => o.GetType() == serviceType);
+                }
+
+                if (obj == null)
+                {
+                    obj = ActivatorUtilities.GetServiceOrCreateInstance(provider, serviceType);
+                }
 
                 var jsonContent = context.DeliverMessage.Content;
                 var message = _messagePacker.UnPack(jsonContent);