c# - 使用 Unity 2 和 MVC 3 将类注入(inject)身份验证属性

Question

我已经阅读了很多指出如何做到这一点的文章，即:

Stack overflow solution

Brad Wilsons excellent tutorial

这些看起来确实运作良好，但是当我遵循此处的一些指南时

Securing your ASP.NET MVC 3 Application

我好像来了个收割机。对我来说，问题是当我将我的 AuthorizationAttribute 添加为 GlobalFilter 而不是仅仅装饰 Controller /操作时。尽管依赖解析器似乎被调用并设置了我公开的 [Dependancy] 属性，但当它实际涉及到我覆盖 AuthorizeAttribute 的 OnAuthorization() 方法的代码部分时，我的公共(public) [Dependency] 属性为空。

当我将其从全局过滤器中移除并装饰 Controller 时，它似乎可以正常工作。

如果需要更多信息，我可以发布代码。

编辑:为了进一步扩展这里是我的一些代码:

全局.asax.cs

 public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {                        
        // If I have this here the my [Dependency] attribute does not keep it's value
        // If I remove it and decorate the controller the [Dependency] attribute keeps it value
        filters.Add(new BasicAuthenticationAttribute());
        filters.Add(new HandleErrorAttribute());
    }

protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();

        RegisterGlobalFilters(GlobalFilters.Filters);
        RegisterRoutes(RouteTable.Routes);

        // injection of services and data contexts
        var container = new UnityContainer();

        // injections for services
        RegisterUnityServices(container);

        // Filter provides to allow injection into attribute filters
        RegisterUnityFilters(container);

    }

    private void RegisterUnityServices(UnityContainer container)
    {
        container.RegisterType<IDataContext, CDAXDataContext>();

        container.RegisterType<IUploadService, UploadService>();
        container.RegisterType<IAuthenticationService, AuthenticationService>();

        // add more services here ...            
        DependencyResolver.SetResolver(new Models.UnityDependencyResolver(container));            
    }

    private void RegisterUnityFilters(UnityContainer container)
    {
        var oldProvider = FilterProviders.Providers.Single(f => f is FilterAttributeFilterProvider);
        FilterProviders.Providers.Remove(oldProvider);

        var provider = new UnityFilterAttributeFilterProvider(container);
        FilterProviders.Providers.Add(provider);            
    }

我的 Unity 类取自布拉德·威尔逊的例子:

    public class UnityDependencyResolver : IDependencyResolver
{
    readonly IUnityContainer _container;

    public UnityDependencyResolver(IUnityContainer container)
    {
        this._container = container;
    }

    public object GetService(Type serviceType)
    {
        try
        {
            return _container.Resolve(serviceType);
        }
        catch
        {
            return null;
        }
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        try
        {
            return _container.ResolveAll(serviceType);
        }
        catch
        {
            return new List<object>();
        }
    }
}

和

    public class UnityFilterAttributeFilterProvider : FilterAttributeFilterProvider 
{
    private IUnityContainer _container;

    public UnityFilterAttributeFilterProvider(IUnityContainer container)
    {
        _container = container;
    }

    public override IEnumerable<Filter> GetFilters(ControllerContext controllerContext, ActionDescriptor actionDescriptor)
    {
        var filters = base.GetFilters(controllerContext, actionDescriptor);

        foreach (var filter in filters)
        {
            _container.BuildUp(filter.Instance);
        }

        return filters;
    }

    protected override IEnumerable<FilterAttribute> GetControllerAttributes(
                ControllerContext controllerContext,
                ActionDescriptor actionDescriptor)
    {

        var attributes = base.GetControllerAttributes(controllerContext,
                                                      actionDescriptor);
        foreach (var attribute in attributes)
        {
            _container.BuildUp(attribute.GetType(), attribute);
        }

        return attributes;
    }

    protected override IEnumerable<FilterAttribute> GetActionAttributes(
                ControllerContext controllerContext,
                ActionDescriptor actionDescriptor)
    {

        var attributes = base.GetActionAttributes(controllerContext,
                                                  actionDescriptor);
        foreach (var attribute in attributes)
        {
            _container.BuildUp(attribute.GetType(), attribute);
        }

        return attributes;
    }
}

以及我的 BasicAuthenticationAttribute 的基础，其中我设置了 [Dependency] 属性，但在触发 OnAuthorization 方法时不维护该值。

    public class BasicAuthenticationAttribute : AuthorizeAttribute
{
    [Dependency]
    public IAuthenticationService Authentication { get; set; }

    private void CacheValidateHandler(HttpContext context, object data, ref HttpValidationStatus validationStatus)
    {
        validationStatus = OnCacheAuthorization(new HttpContextWrapper(context));
    }

    public override void OnAuthorization(AuthorizationContext filterContext)
    {
       // code here that uses the Authentication attribute but it's null
    }

Answer 1

我认为您需要在属性类中调用 DependencyResolver...不确定 [Dependency] 是否属性在这里工作...所以在 OnAuthorization方法调用 IAuthenticationService authentication = DependencyResolver.Current.GetService<IAuthenticationService>();