c# - 我可以让 WebApi 与 IoC Aspects/Interceptor 一起工作吗

Question

我有 WCF 背景，我成功地将 IoC 与方面/拦截器结合使用来抽象功能，例如身份验证和日志记录。我会简单地将所需的接口(interface)添加到方面构造函数，就像您使用任何典型的 IoC 设置一样。

我现在正尝试将相同类型的过程应用于 webapi，但由于 Controller 继承自 ApiController 并且不实现接口(interface)。我假设可能有不同的应用方面的方式？

public class MyController: ApiController
{
    private readonly IUnitOfWork _unitOfWork;
    private readonly ILoginService _loginService;
    private readonly ILog _log;

    public LoginController(ILoginService loginService, IUnitOfWork unitOfWork, ILog log)
    {
        this._loginService = loginService;
        this._unitOfWork = unitOfWork;
        this._log = log;
    }

    // I WANT TO INTERCEPT THIS METHOD USING UserTokenAuthenticationInterceptor 
    public HttpResponseMessage Get(Guid id)
    {
        _log.Log(log something);
        // some code thats gets some data using this._loginService
        _log.Log(log the save);
         _unitOfWork.Save();
    }
}

看点

public class UserTokenAuthenticationInterceptor : IInterceptionBehavior 
{
    private readonly ILoginService _loginService;
    private readonly ILog _log;

    public UserTokenAuthenticationInterceptor(ILog log, ILoginService loginService)
    {
        this._log = log;
        this._loginService = loginService;
    }

    public IMethodReturn Invoke(IMethodInvocation input, GetNextInterceptionBehaviorDelegate getNext)
    {
        _log.Log(log entering authentication aspect);
        // do some authentication here using this._loginService
        _log.Log(log exiting authentication aspect);
    }

    public IEnumerable<Type> GetRequiredInterfaces()
    {
        return Type.EmptyTypes;
    }

    public bool WillExecute { get { return true; }}
}

容器注册:

container.RegisterType<IUnitOfWork, UnitOfWork.UnitOfWork>(new HierarchicalLifetimeManager());
container.RegisterType<ILoginService , LoginService>();
container.RegisterType<ILog, LogService>();

我在这个例子中使用了 unity。谁能指出我正确的方向？

Answer 1

感谢大家的帮助，我终于弄明白了。

我从这篇文章中得到了大部分答案 https://unity.codeplex.com/discussions/446780

我使用了以下 nuget 包。

• Unity(我先加了这1个)
• Unity.WebApi(如果不先添加unity会有unity版本问题)

首先，我需要一个新的 IFilterProvider 实现。它的工作是向容器注册所有 Action 过滤器。

public class UnityActionFilterProvider : ActionDescriptorFilterProvider, IFilterProvider
{
    private readonly IUnityContainer container;

    public UnityActionFilterProvider(IUnityContainer container)
    {
        this.container = container;
    }

    public new IEnumerable<FilterInfo> GetFilters(HttpConfiguration configuration, HttpActionDescriptor actionDescriptor)
    {
        var filters = base.GetFilters(configuration, actionDescriptor);

        foreach (var filter in filters)
        {
            container.BuildUp(filter.Instance.GetType(), filter.Instance);
        }

        return filters;
    }
}

然后需要一个注册方法，注册新的actionfilterprovider，去掉原来的webapi实现。这需要在 Unity.WebApi nuget 包创建的 UnityConfig.cs 文件中的 RegisterComponents() 方法中执行。

public static void RegisterFilterProviders(IUnityContainer container)
{
    var providers = GlobalConfiguration.Configuration.Services.GetFilterProviders().ToList();

    GlobalConfiguration.Configuration.Services.Add(typeof(System.Web.Http.Filters.IFilterProvider),
                                                    new UnityActionFilterProvider(container));

    var defaultprovider = providers.First(p => p is ActionDescriptorFilterProvider);

    GlobalConfiguration.Configuration.Services.Remove(typeof(System.Web.Http.Filters.IFilterProvider), defaultprovider);

}

在同一个 RegisterComponents() 方法中我注册了我的类型

container.RegisterType<IUnitOfWork, UnitOfWork.UnitOfWork>(new HierarchicalLifetimeManager());
container.RegisterType<ILoginService , LoginService>();
container.RegisterType<ILog, LogService>();    

接下来，我需要创建一个基于 AuthorizeAttribute 的类。

public class UserTokenAuthenticationAttribute : AuthorizeAttribute
{
    private ILoginService _loginService;

    // This is the magic part - Unity reads this attribute and sets injects the related property. This means no parameters are required in the constructor.
    [Microsoft.Practices.Unity.Dependency]
    public ILoginService LoginService
    { 
        get
        {
            return this._loginService;
        } 
        set
        {
            this._loginService = value;
        }  
    }

    protected override bool IsAuthorized(HttpActionContext actionContext)
    {
        // Authorise code goes here using injected this._loginService
    }
}      

还需要一个日志 Action 过滤器ActionFilterAttribute

public sealed class LogAttribute : ActionFilterAttribute
    {
        private ILog _log;

        // This is the magic part - Unity reads this attribute and sets injects the related property. This means no parameters are required in the constructor.
        [Microsoft.Practices.Unity.Dependency]
        public ILog Log
        { 
            get
            {
                return this._log;
            } 
            set
            {
                this._log = value;
            }  
        }

        public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
        {
            this._log.Info("Exited " + actionContext.Request.Method);
        }

        public override void OnActionExecuting(HttpActionContext actionContext)
        {
            this._log.Info("Entering" + actionContext.Request.Method);
        }
    }    

现在让我们配置 webapi Controller 。我们需要用我们的新属性来装饰这个类

[UserTokenAuthentication] // magic attribute in use
[Log] // magic attribute in use
public class MyController: ApiController
{
    private readonly IUnitOfWork _unitOfWork;
    private readonly ILoginService _loginService;
    private readonly ILog _log;

    public MyController(ILoginService loginService, IUnitOfWork unitOfWork, ILog log)
    {
        this._loginService = loginService;
        this._unitOfWork = unitOfWork;
        this._log = log;
    }

    [System.Web.Http.AllowAnonymous] // doesnt require authentication as were not logged in yet
    public HttpResponseMessage Get(Guid id)
    {
        _log.Log(log something);
        // some code thats gets some data using this._loginService
        _log.Log(log the save);
         _unitOfWork.Save();
    }

    public HttpResponseMessage GetMyDetails(Guid id)
    {
        _log.Log(log something);
        // some code thats gets some data using this._loginService
        _log.Log(log the save);
         _unitOfWork.Save();
    }
}