asp.net-web-api - AutoFac 与 Web Api，仍在寻找无参数构造函数

Question

我的 WebApi 项目中有以下类，并且从 Global.ASAX 类调用 RegisterContainer() 方法。我正在我的 api Controller 中注入(inject) Service。问题是它抛出异常并且没有得到实例化纠正。它说找不到无参数 Controller 。知道我的代码有什么问题

public class IocConfig
{
    #region Public Methods and Operators

    /// <summary>
    ///     Adds dependencies into the container
    /// </summary>
    /// <returns></returns>
    public static void RegisterContainer()
    {
        var builder = new ContainerBuilder();

        builder.RegisterControllers(Assembly.GetExecutingAssembly());
        builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
        IContainer container = builder.Build();
        DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
        GlobalConfiguration.Configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);
        RegisterModules(builder);
        RegisterControllers(builder);
    }

    #endregion

    #region Methods

    private static void RegisterControllers(ContainerBuilder builder)
    {
        builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
    }

    private static void RegisterDependencyResolver(IContainer container, ContainerBuilder builder)
    {
        IDependencyResolver resolver = new AutofacWebApiDependencyResolver(container);

        DependencyResolver.SetResolver(resolver);
    }

    private static void RegisterModules(ContainerBuilder builder)
    {

        builder.RegisterModule(new DomainModule());
        builder.RegisterModule(new RepositoryModule());
        builder.RegisterModule(new ServiceFacadeModule());
        builder.RegisterModule(new MappingModule());

    }

    #endregion
}

}

更新:

我已经更改了这一点，并且仅向 Global.Asax 添加了以下几行。

protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        GlobalConfiguration.Configure(WebApiConfig.Register);
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        BundleConfig.RegisterBundles(BundleTable.Bundles);
        //IocConfig.RegisterContainer();
        //WebApiConfig.Register(GlobalConfiguration.Configuration);

        var builder = new Autofac.ContainerBuilder();
        builder.RegisterControllers(typeof(WebApiApplication).Assembly).PropertiesAutowired();
        builder.RegisterModule(new RepositoryModule());
        builder.RegisterModule(new ServiceFacadeModule());
        builder.RegisterModule(new RepositoryModule());
        builder.RegisterModule(new MappingModule());
        builder.RegisterModule(new DomainModule());
        var container = builder.Build();
        DependencyResolver.SetResolver(new AutofacDependencyResolver(container));


    }

Answer 1

您正在尝试在容器构建后注册模块。

您需要转移调用

RegisterModules(builder);

在使用 builder.Build() 创建容器之前:

RegisterModules(builder);
IContainer container = builder.Build();

在更新后的代码中，您现在缺少两件事:

• 使用 RegisterApiControllers 注册您的 Api Controller
• 设置AutofacWebApiDependencyResolver

所以你的代码应该是这样的:

var builder = new Autofac.ContainerBuilder();
builder.RegisterControllers(typeof(WebApiApplication).Assembly).PropertiesAutowired();
builder.RegisterApiControllers(typeof(WebApiApplication).Assembly).PropertiesAutowired();
builder.RegisterModule(new RepositoryModule());
builder.RegisterModule(new ServiceFacadeModule());
builder.RegisterModule(new RepositoryModule());
builder.RegisterModule(new MappingModule());
builder.RegisterModule(new DomainModule());
var container = builder.Build();
DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
GlobalConfiguration.Configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);