C# 如何将IHttpRouteConstraint注入web api？

正如标题所述，我需要能够将服务注入到web api约束类中。我在我的c#webApi项目中使用SimpleInjector

在我的webApiConfig.cs中，我有这个

// add constraint resolvers
var constraintResolver = new DefaultInlineConstraintResolver();
constraintResolver.ConstraintMap.Add("dynamicName", typeof(DynamicRouteConstraint));

// routing
config.MapHttpAttributeRoutes(constraintResolver);

我的订制合同是这样的

public class DynamicRouteConstraint : IHttpRouteConstraint
{
    private IDynamicRouteService _service;

    public DynamicRouteConstraint(IDynamicRouteService service)
    {
        _service = service;
    }

    public bool Match(System.Net.Http.HttpRequestMessage request, IHttpRoute route, string parameterName, IDictionary<string, object> values, HttpRouteDirection routeDirection)
    {
        return _service.Match(values[parameterName].ToString());
    }
}

更新：

所以我查看了类的实现，发现这个类没有使用容器解析器，而是使用激活器类来创建实例，这可能会导致默认构造函数实例的问题

---

在我看来，您可能需要为IInlineConstraintResolver创建一个自定义实现，或者从DynamicRouteConstraint构造函数中删除参数IDynamicRouteService，并通过其他方式初始化实例

你用的是软件包，对吗？如果我猜对了，请检查我的答案。您使用的是SimpleInjector，但SimpleInjector的WebAPI集成包附带了另一个关联库，它提供了WebAPI兼容的container.edited问题，包括startup.cs和SimpleInjector.register函数，从而实现了所需的功能我想我已经解决了，引发此异常的不是简单的注入器，而是DefaultInlineConstraintResolver类。看我的回答。

container.RegisterWebApiRequest<IDynamicRouteService, DynamicRouteService>();

public class DynamicRouteService : IDynamicRouteService
{
    private IModuleService _service;

    public DynamicRouteService(IModuleService service)
    {
        _service = service;
    }

    public ICollection<DynamicRouteModel> GetRoutes()
    {
        var list = new List<DynamicRouteModel>();

        // custom code usually here

        return list;
    }

    public void Clear()
    {
        // custom code usually here
    }

    public bool Match(string name)
    {
        // custom code usually here
        return false;
    }

}

public static Container Register(HttpConfiguration apiConfig)
{
    var container = new Container();

    container.RegisterPerWebRequest<HttpContextBase>(() => new HttpContextWrapper(HttpContext.Current));
    container.RegisterPerWebRequest<HttpConfiguration>(() => apiConfig);

    // EnableHttpRequest and IDynamicNameService are needed to get the name of the module
    // that is requested via the DynamicDataController
    container.EnableHttpRequestMessageTracking(apiConfig);
    container.RegisterWebApiRequest<IDynamicModuleService, DynamicRouteService>();

    // service for dynamicRoute checking
    container.Register<IDynamicRouteService, DynamicRouteService>();

    // This is an extension method from the integration package.
    container.RegisterWebApiControllers(apiConfig);

    container.RegisterMvcControllers(Assembly.GetExecutingAssembly());

    container.Verify();

    DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));

    apiConfig.DependencyResolver = new SimpleInjectorWebApiDependencyResolver(container);

    return container;
}

public void Configuration(IAppBuilder app)
{
    // This is a self hosted webapi project..
    HttpConfiguration apiConfig = new HttpConfiguration();

    // confgi oauth
    OAuthConfig.Register(app);

    // simple injector
    var container = SimpleInjectorConfig.Register(apiConfig);

    AutoMapperConfig.RegisterMappings();
    AreaRegistration.RegisterAllAreas();
    WebApiConfig.Register(apiConfig, container);
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);

    app.UseWebApi(apiConfig);
}