我正在使用 webapi、unity 和 mvc。我收到错误“确保控制器具有无参数公共构造函数”。我已经看到类似问题的解决方案，但仍然无法使其工作。我已经安装了 unity.webapi 并且似乎拥有所有必要的参考：
- Microsoft.Practices.Unity - 运行时：v4.0.30319，版本：3.5.0.0
- Microsoft.Practices.Unity.Mvc - 运行时：v4.0.30319，版本：3.5.0.0
- Unity.WebApi - 运行时：v4.0.30319，版本：5.1.0.0
- System.Web.Http - 运行时：v4.0.30319，版本：5.2.2.0
- System.Web.Mvc - 运行时：v4.0.30319，版本：5.2.2.0
我验证了所有内容都与该网站上的内容相符：
http://www.asp.net/mvc/overview/releases/how-to-upgrade-an-aspnet-mvc-4-and-web-api-project-to-aspnet-mvc-5-and-web- API-2 http://www.asp.net/mvc/overview/releases/how-to-upgrade-an-aspnet-mvc-4-and-web-api-project-to-aspnet-mvc-5-and-web-api-2
这是我所拥有的：
引导程序：
public static class Bootstrapper
{
public static IUnityContainer Initialise()
{
var container = BuildUnityContainer();
DependencyResolver.SetResolver(new UnityDependencyResolver(container));
return container;
}
private static IUnityContainer BuildUnityContainer()
{
var container = new UnityContainer();
container.RegisterType<IDatabaseFactoryHouseDB, DatabaseFactoryHouseDB>(new HierarchicalLifetimeManager());
container.RegisterType<UnitOfWorkHouseDB>();
// repositories
container.RegisterType<IEmployeeRepository, EmployeeRepository>();
// services
container.RegisterType<IEmployeeService, EmployeeService>();
RegisterTypes(container);
return container;
}
public static void RegisterTypes(IUnityContainer container) { }
}
全局.asax：
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
Database.SetInitializer<HouseDBContext>(null);
Bootstrapper.Initialise();
//required for setting routes in the attributes of a controller method
GlobalConfiguration.Configuration.EnsureInitialized();
}
}
API控制器：
public class EmployeeApiController : ApiController
{
private readonly IEmployeeService employeeService;
public EmployeeApiController(IEmployeeService employeeService)
{
this.employeeService = employeeService;
}
// rest of controller
}
WebApi配置：
public static void Register(HttpConfiguration config)
{
config.MapHttpAttributeRoutes();
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
// use json strings as the default return value for the app
config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));
// Uncomment the following line of code to enable query support for actions with an IQueryable or IQueryable<T> return type.
// To avoid processing unexpected or malicious queries, use the validation settings on QueryableAttribute to validate incoming queries.
// For more information, visit http://go.microsoft.com/fwlink/?LinkId=279712.
//config.EnableQuerySupport();
// To disable tracing in your application, please comment out or remove the following line of code
// For more information, refer to: http://www.asp.net/web-api
config.EnableSystemDiagnosticsTracing();
}
统一配置：
public static class UnityConfig
{
public static void RegisterComponents()
{
var container = new UnityContainer();
GlobalConfiguration.Configuration.DependencyResolver = new UnityDependencyResolver(container);
}
}
不知道我错过了什么。
Edit:我注意到我的 App_Start 文件夹中有一个 UnityConfig 类。在查看了 Sarathy 的评论后，我意识到它没有被调用。我在 global.asax 中注释掉了引导程序初始化，并添加了 UnityConfig.RegisterComponents() 行，所以现在我的 global.asax 看起来像这样：
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
UnityConfig.RegisterComponents(); // <--- added
AreaRegistration.RegisterAllAreas();
GlobalConfiguration.Configure(WebApiConfig.Register);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
Database.SetInitializer<HouseDBContext>(null);
//Bootstrapper.Initialise(); <-- not using bootstrapper anymore
//required for setting routes in the attributes of a controller method
GlobalConfiguration.Configuration.EnsureInitialized();
}
}
我的 UnityConfig 如下所示：
public static class UnityConfig
{
public static void RegisterComponents()
{
var container = new UnityContainer();
// register all your components with the container here
// it is NOT necessary to register your controllers
// e.g. container.RegisterType<ITestService, TestService>();
container.RegisterType<IDatabaseFactoryHouseDB, DatabaseFactoryHouseDB>(new HierarchicalLifetimeManager());
//container.RegisterType<IUnitOfWork>();
container.RegisterType<UnitOfWorkHouseDB>();
// repositories
container.RegisterType<IEmployeeRepository, EmployeeRepository>();
// services
container.RegisterType<IEmployeeService, EmployeeService>();
GlobalConfiguration.Configuration.DependencyResolver = new Unity.WebApi.UnityDependencyResolver(container);
}
}
但我仍然收到无参数构造函数错误。有趣的是，即使我添加了一个无参数构造函数：
public class EmployeeApiController : ApiController
{
private readonly IEmployeeService employeeService;
public EmployeeApiController()
: base()
{
}
public EmployeeApiController(IEmployeeService employeeService)
{
this.employeeService = employeeService;
}
}
使用 unityconfig 方法时仍然出现错误。使用引导程序，我没有收到错误，但我的服务未初始化。
我完全困惑了。不知怎的，我觉得我正在混合 MVC 和 WebApi，但事情没有正确解决......
EDIT 2:
我查看了无参数构造函数错误的内部异常，并注意到它提到了我的 IUnitOfWork 类：
“依赖关系解析失败，类型 =
\“AngularMVC.Controllers.EmployeeApiController\”，名称=
\“（无）\”。\r\n异常发生时： 解析时。\r\n异常
是：InvalidOperationException -当前类型，
AngularMVC.Models.Interfaces.IUnitOfWork，是一个接口，不能
被建造。您是否缺少类型
映射?\r\n-------------------------------------------------------- --\r\n在
异常发生时，容器为:\r\n\r\n 正在解决
AngularMVC.Controllers.EmployeeApiController，（无）\r\n 正在解析
构造函数的参数“employeeService”
AngularMVC.Controllers.EmployeeApiController(AngularMVC.Services.IEmployeeService
employeeService)\r\n 正在解决
AngularMVC.Services.EmployeeService,(none)（映射自
AngularMVC.Services.IEmployeeService，（无））\r\n 正在解析
构造函数的参数“unitOfWork”
AngularMVC.Services.EmployeeService(AngularMVC.Models.Repositories.IEmployeeRepository
员工存储库，AngularMVC.Models.Interfaces.IUnitOfWork
工作单元)\r\n 正在解析
AngularMVC.Models.Interfaces.IUnitOfWork，（无）\r\n"
这只是这个：
public interface IUnitOfWork
{
void Commit();
}
当我在 UnityConfig 中执行以下操作时：
container.RegisterType<IUnitOfWork>();
IUnitOfWork sm = container.Resolve<IUnitOfWork>();
我收到同样的错误，指出“当前类型 AngularMVC.Models.Interfaces.IUnitOfWork 是一个接口，无法构造。您是否缺少类型映射？”
