与ASP.NET Core和MVC6（核心）的统一

2 回答

• 7

  经过一些研究后，我想出了以下解决方案来解决我的问题：

  Use Unity with ASP
  为了能够与ASP一起使用Unity，我需要一个自定义的IServiceProvider（ASP Documentation），所以我为IUnityContainer编写了一个包装器，看起来像这样

  public class UnityServiceProvider : IServiceProvider
  {
      private IUnityContainer _container;
  
      public IUnityContainer UnityContainer => _container;
  
      public UnityServiceProvider()
      {
          _container = new UnityContainer();
      }
  
      #region Implementation of IServiceProvider
  
      /// <summary>Gets the service object of the specified type.</summary>
      /// <returns>A service object of type <paramref name="serviceType" />.-or- null if there is no service object of type <paramref name="serviceType" />.</returns>
      /// <param name="serviceType">An object that specifies the type of service object to get. </param>
      public object GetService(Type serviceType)
      {
          //Delegates the GetService to the Containers Resolve method
          return _container.Resolve(serviceType);
      }
  
      #endregion
  }
  

  另外，我不得不改变我的Startup类中的ConfigureServices方法的签名：

  public void ConfigureServices(IServiceCollection services)
  

  对此：

  public IServiceProvider ConfigureServices(IServiceCollection services)
  

  现在我可以返回我的自定义IServiceProvider，它将被用来代替默认值 .
  完整的ConfigureServices方法显示在底部的Wire up部分 .

  Resolving Controllers
  我找到了this blog post . 从中我了解到MVC使用IControllerActivator接口来处理Controller实例化 . 所以我写了我自己的，看起来像这样：

  public class UnityControllerActivator : IControllerActivator
  {
      private IUnityContainer _unityContainer;
  
      public UnityControllerActivator(IUnityContainer container)
      {
          _unityContainer = container;
      }
  
      #region Implementation of IControllerActivator
  
      public object Create(ControllerContext context)
      {
          return _unityContainer.Resolve(context.ActionDescriptor.ControllerTypeInfo.AsType());
      }
  
  
      public void Release(ControllerContext context, object controller)
      {
          //ignored
      }
  
      #endregion
  }
  

  现在，如果激活了Controller类，它将使用我的UnityContainer进行实例化 . 因此我的UnityContainer必须知道如何解析任何控制器！

  Next Problem: Use the default IServiceProvider
  现在，如果我在ASP.NET中注册Mvc等服务，我通常会这样做：

  services.AddMvc();
  

  现在，如果我使用UnityContainer，则无法解析所有MVC依赖项，因为它们未注册 . 所以我可以注册它们（比如AutoFac）或者我可以创建一个UnityContainerExtension . 我选择了扩展并提出以下两个条款：
  UnityFallbackProviderExtension

  public class UnityFallbackProviderExtension : UnityContainerExtension
  {
      #region Const
  
      ///Used for Resolving the Default Container inside the UnityFallbackProviderStrategy class
      public const string FALLBACK_PROVIDER_NAME = "UnityFallbackProvider";
  
      #endregion
  
      #region Vars
  
      // The default Service Provider so I can Register it to the IUnityContainer
      private IServiceProvider _defaultServiceProvider;
  
      #endregion
  
      #region Constructors
  
      /// <summary>
      /// Creates a new instance of the UnityFallbackProviderExtension class
      /// </summary>
      /// <param name="defaultServiceProvider">The default Provider used to fall back to</param>
      public UnityFallbackProviderExtension(IServiceProvider defaultServiceProvider)
      {
          _defaultServiceProvider = defaultServiceProvider;
      }
  
      #endregion
  
      #region Overrides of UnityContainerExtension
  
      /// <summary>
      /// Initializes the container with this extension's functionality.
      /// </summary>
      /// <remarks>
      /// When overridden in a derived class, this method will modify the given
      /// <see cref="T:Microsoft.Practices.Unity.ExtensionContext" /> by adding strategies, policies, etc. to
      /// install it's functions into the container.</remarks>
      protected override void Initialize()
      {
          // Register the default IServiceProvider with a name.
          // Now the UnityFallbackProviderStrategy can Resolve the default Provider if needed
          Context.Container.RegisterInstance(FALLBACK_PROVIDER_NAME, _defaultServiceProvider);
  
          // Create the UnityFallbackProviderStrategy with our UnityContainer
          var strategy = new UnityFallbackProviderStrategy(Context.Container);
  
          // Adding the UnityFallbackProviderStrategy to be executed with the PreCreation LifeCycleHook
          // PreCreation because if it isnt registerd with the IUnityContainer there will be an Exception
          // Now if the IUnityContainer "magically" gets a Instance of a Type it will accept it and move on
          Context.Strategies.Add(strategy, UnityBuildStage.PreCreation);
      }
  
      #endregion
  }
  

  UnityFallbackProviderStrategy ：

  public class UnityFallbackProviderStrategy : BuilderStrategy
  {
      private IUnityContainer _container;
  
      public UnityFallbackProviderStrategy(IUnityContainer container)
      {
          _container = container;
      }
  
      #region Overrides of BuilderStrategy
  
      /// <summary>
      /// Called during the chain of responsibility for a build operation. The
      /// PreBuildUp method is called when the chain is being executed in the
      /// forward direction.
      /// </summary>
      /// <param name="context">Context of the build operation.</param>
      public override void PreBuildUp(IBuilderContext context)
      {
          NamedTypeBuildKey key = context.OriginalBuildKey;
  
          // Checking if the Type we are resolving is registered with the Container
          if (!_container.IsRegistered(key.Type))
          {
              // If not we first get our default IServiceProvider and then try to resolve the type with it
              // Then we save the Type in the Existing Property of IBuilderContext to tell Unity
              // that it doesnt need to resolve the Type
              context.Existing = _container.Resolve<IServiceProvider>(UnityFallbackProviderExtension.FALLBACK_PROVIDER_NAME).GetService(key.Type);
          }
  
          // Otherwise we do the default stuff
          base.PreBuildUp(context);
      }
  
      #endregion
  }
  

  现在，如果我的UnityContainer没有注册的东西，它只是询问默认的提供商 .
  我从几篇不同的文章中学到了所有这些

  • MSDN Unity article

  • Auto-Mocking Unity Container Extension

  • Custom Object Factory Unity Extension

  这种方法的好处是我现在也可以"mix"依赖 . 如果我需要来自ASP的任何服务和IOptions接口，我的UnityContainer将解析所有这些依赖项并将它们注入我的控制器！
  唯一要记住的是，如果我使用任何自己的依赖项，我必须使用Unity注册我的Controller类，因为默认的IServiceProvider无法再解析我的控制器依赖项 .

  Finally: Wire up
  现在在我的项目中，我使用不同的服务（ASP选项，带选项的MVC） . 为了使它全部工作，我的ConfigureServices方法现在看起来像这样：

  public IServiceProvider ConfigureServices(IServiceCollection services)
      {
          // Add all the ASP services here
          // #region ASP
          services.AddOptions();
          services.Configure<WcfOptions>(Configuration.GetSection("wcfOptions"));
  
          var globalAuthFilter = new AuthorizationPolicyBuilder()
              .RequireAuthenticatedUser()
              .Build();
  
          services.AddMvc(options => { options.Filters.Add(new AuthorizeFilter(globalAuthFilter)); })
                  .AddJsonOptions
              (
                  options => options.SerializerSettings.ContractResolver = new DefaultContractResolver()
              );
          // #endregion ASP
  
          // Creating the UnityServiceProvider
          var unityServiceProvider = new UnityServiceProvider();
  
          IUnityContainer container = unityServiceProvider.UnityContainer;
  
          // Adding the Controller Activator
          // Caution!!! Do this before you Build the ServiceProvider !!!
          services.AddSingleton<IControllerActivator>(new UnityControllerActivator(container));
  
          //Now build the Service Provider
          var defaultProvider = services.BuildServiceProvider();
  
          // Configure UnityContainer
          // #region Unity
  
          //Add the Fallback extension with the default provider
          container.AddExtension(new UnityFallbackProviderExtension(defaultProvider));
  
          // Register custom Types here
  
          container.RegisterType<ITest, Test>();
  
          container.RegisterType<HomeController>();
          container.RegisterType<AuthController>();
  
          // #endregion Unity
  
          return unityServiceProvider;
      }
  

  因为我在过去一周里学到了大部分关于DI的知识，所以我希望我没有打破任何大的主要/模式，如果是这样，请告诉我！

  回复于 2024-05-02T14:26:07+08:00
• 35

  对于ASP.Net Core 2.0,2.1和Unity，Unity提供官方解决方案作为NuGet包的作者：NuGetPackage

  这是带有示例的Git存储库：Git repo

  用法非常简单（来自Git repo主页）：

  public static IWebHost BuildWebHost(string[] args) =>
  WebHost.CreateDefaultBuilder(args)
         .UseUnityServiceProvider()   <---- Add this line
         .UseStartup<Startup>()
         .Build();
  

  here是用于ASP.Net Core的Unity DI的示例 .

  我在我的ASP.Net Core应用程序中使用此解决方案并且运行良好 .

  回复于 2024-05-02T14:26:07+08:00