Ninject:属性注入ActionFilterAttribute

Question

我想通过Ninject在ActionFilterAttribute中实现DI。我找到了这本手册（实际上我今天已经读了几十本），但它是为Unity准备的。我在Ninject上实现它的尝试在这里：

public class MyFilter : ActionFilterAttribute
{
    [Inject]
    public IDepend Depend { get; set; }
    // another code
}

绑定：

public class NinjectResolver : IDependencyResolver
{
    // another code
    private IKernel AddRequestBindings(IKernel kernel)
    {
        // another code
        kernel.Bind<IDepend>().To<Depend>();
        return kernel;
    }
}

自定义筛选器提供程序：

public class WebApiNinjectActionFilterProvider : ActionDescriptorFilterProvider, IFilterProvider
{
    private readonly IKernel _kernel;
    private readonly IEnumerable<IFilterProvider> _filterProviders;
    public WebApiNinjectActionFilterProvider(IKernel kernel, IEnumerable<IFilterProvider> filterProviders)
    {
        _kernel = kernel;
        _filterProviders = filterProviders;
    }
    public new IEnumerable<FilterInfo> GetFilters(HttpConfiguration configuration, HttpActionDescriptor actionDescriptor)
    {
        var filters = _filterProviders.SelectMany(fp => fp.GetFilters(configuration, actionDescriptor)).ToList();
        foreach (var filter in filters)
        {
            // GET ActivationException HERE!!!!!
            _kernel.Inject(filter.Instance);
        }
        return filters;
    }
    public static void RegisterFilterProviders(IKernel ninjectKernel)
    {
        var providers = GlobalConfiguration.Configuration.Services.GetFilterProviders().ToList();
        GlobalConfiguration.Configuration.Services.Add(typeof(IFilterProvider),
                                                       new WebApiNinjectActionFilterProvider(ninjectKernel, providers));
        var defaultprovider = providers.First(i => i is ActionDescriptorFilterProvider);
        GlobalConfiguration.Configuration.Services.Remove(typeof(IFilterProvider), defaultprovider);
    }
}

从WebApiConfig:调用

    public static void Register(HttpConfiguration config)
    {
        var ninjectKernel = new StandardKernel();
        config.DependencyResolver = new NinjectResolver(ninjectKernel);
        WebApiNinjectActionFilterProvider.RegisterFilterProviders(ninjectKernel);
    }

最后行动：

    [MyFilter]
    public async Task<string> Test()
    {
        return "Hello world";
    }

问题是我在这行得到了一个ActivationException：

_kernel.Inject(filter.Instance);

ActivationException的激活路径：

2） 将依赖IDepend注入MyFilter 类型的属性Depend

1） MyFilter 请求

若要将相同的属性注入控制器，它会注入fine。有什么想法可以改进我的代码吗？

Answer 1

我做IActionFilter DI的方式不对。我在Mark Seemann的这篇博客文章中找到了正确的方法。

通过Ninject的DI是这样实现的：

var myFilter = new MyFilter(ninjectKernel.Get<IDepend>());
config.Filters.Add(myFilter);