所以经过一些研究，我想出了以下解决问题的方法：
将 Unity 与 ASP 结合使用
为了能够在 ASP 中使用 Unity，我需要一个自定义 IServiceProvider (ASP Documentation)，所以我为 IUnityContainer 编写了一个包装器，如下所示
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
}
我还必须在我的 Startup 类中更改 ConfigureServices 方法的签名：
public void ConfigureServices(IServiceCollection services)
到这里：
public IServiceProvider ConfigureServices(IServiceCollection services)
现在我可以返回我的自定义 IServiceProvider，它将被使用而不是默认的。
完整的 ConfigureServices 方法显示在底部的 Wire up 部分中。
解析控制器
我找到了this blog post。从中我了解到 MVC 使用 IControllerActivator 接口来处理控制器实例化。所以我写了自己的，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，如果一个 Controller 类被激活，它将被我的 UnityContainer 实例化。因此我的 UnityContainer 必须知道如何解析任何控制器！
下一个问题：使用默认的 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，所有 MVC 依赖项都无法解析，因为它们没有注册。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了以下两个类别：
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 没有注册某些东西，它只需向默认提供者询问它。
我从几篇不同的文章中学到了所有这些
这种方法的好处是我现在还可以“混合”依赖项。如果我需要我的任何服务和来自 ASP 的 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，如果我使用我自己的任何依赖项，我必须向 Unity 注册我的 Controller 类，因为默认的 IServiceProvider 不能再解析我的控制器依赖项。
最后：连线
现在在我的项目中，我使用不同的服务（ASP 选项、带有选项的 MVC）。为了让这一切正常工作，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;
}
由于我在过去一周了解了大部分关于 DI 的知识，所以我希望我没有破坏任何大的 Pricipal/Pattern 如果是这样，请告诉我！