diff --git a/samples/apis/Product.Api/Application/CommandHandler/AddProductTypeCommandHandler.cs b/samples/apis/Product.Api/Application/CommandHandler/AddProductTypeCommandHandler.cs
index f41998d..0a76490 100644
--- a/samples/apis/Product.Api/Application/CommandHandler/AddProductTypeCommandHandler.cs
+++ b/samples/apis/Product.Api/Application/CommandHandler/AddProductTypeCommandHandler.cs
@@ -26,8 +26,7 @@ namespace Product.Api.Application.CommandHandler
         public async Task<CommonCommandResponse> Handle(Command<AddProductTypeRequest, CommonCommandResponse> request, CancellationToken cancellationToken)
         {
             var productType = new Domain.ProductTypeAggregate.ProductType(request.Data.Id, request.Data.Name);
-
-            
+     
              _productTypeRepository.Add(productType);
             ProductTypeAddedDomainEvent productTypeAddedDomainEvent = new ProductTypeAddedDomainEvent
             {
diff --git a/src/Pole.Application/PoleOptionsExtensions.cs b/src/Pole.Application/PoleOptionsExtensions.cs
index 4388c49..a6e5244 100644
--- a/src/Pole.Application/PoleOptionsExtensions.cs
+++ b/src/Pole.Application/PoleOptionsExtensions.cs
@@ -21,7 +21,7 @@ namespace Microsoft.Extensions.DependencyInjection
         }
         public static PoleOptions AutoInjectionDependency(this PoleOptions options)
         {
-            var assemblies = options.ApplicationAssemblies;
+            var assemblies = options.ApplicationAssemblies??throw new Exception("Cant't find ApplicationAssemblies,You must Run  PoleOptions.AddManageredAssemblies First");
 
             foreach (var assembly in assemblies)
             {
@@ -34,10 +34,11 @@ namespace Microsoft.Extensions.DependencyInjection
 
         public static PoleOptions AutoInjectionCommandHandlersAndDomainEventHandlers(this PoleOptions options, ServiceLifetime lifetime = ServiceLifetime.Scoped)
         {
+            var assemblies = options.ApplicationAssemblies ?? throw new Exception("Cant't find ApplicationAssemblies,You must Run  PoleOptions.AddManageredAssemblies First");
             options.Services.AddMediatR(config =>
-            {
+            {              
                 config.AddServiceLifetime(lifetime);
-            }, options.ApplicationAssemblies.ToArray());
+            }, assemblies.ToArray());
             return options;
         }