我正在努力解决使用依赖注入的问题untiy。我已经按照这个链接实现了https://www.asp.net/web-api/overview/advanced/dependency-injection https://www.asp.net/web-api/overview/advanced/dependency-injection
但得到这个错误:
{
"Message": "An error has occurred.",
"ExceptionMessage": "An error occurred when trying to create a controller of type 'WebAPIController'. Make sure that the controller has a parameterless public constructor.",
"ExceptionType": "System.InvalidOperationException",
"StackTrace": " at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)\r\n at System.Web.Http.Controllers.HttpControllerDescriptor.CreateController(HttpRequestMessage request)\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()",
"InnerException": {
"Message": "An error has occurred.",
"ExceptionMessage": "Type 'Fairmoves.Controllers.WebAPIController' does not have a default constructor",
"ExceptionType": "System.ArgumentException",
"StackTrace": " at System.Linq.Expressions.Expression.New(Type type)\r\n at System.Web.Http.Internal.TypeActivator.Create[TBase](Type instanceType)\r\n at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.GetInstanceOrActivator(HttpRequestMessage request, Type controllerType, Func`1& activator)\r\n at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)"
}
}
我的 Web API 控制器:
[RoutePrefix("api/WebAPI")]
public class WebAPIController : ApiController
{
private readonly IUserBusinessService UserBusinessService;
private readonly ILoginBusinessService LoginBusinessService;
//public WebAPIController():base()
//{
//}
public WebAPIController(IUserBusinessService UserBusinessService, ILoginBusinessService LoginBusinessService)
{
this.UserBusinessService = UserBusinessService;
this.LoginBusinessService = LoginBusinessService;
}
[HttpPost]
public IHttpActionResult Login([FromBody]AuthModels.LoginModel model)
{
// string strUserId = credentials.LoginName;
//string strPassword = credentials.Password;
var serviceResultDAO1 = LoginBusinessService.LoginUserSubmit(model.LoginName);
}
}
UnityResolver.cs:
public class UnityResolver:IDependencyResolver
{
protected IUnityContainer container;
public UnityResolver(IUnityContainer container)
{
if (container == null)
{
throw new ArgumentNullException("container");
}
this.container = container;
}
[DebuggerStepThrough]
public object GetService(Type serviceType)
{
try
{
return container.Resolve(serviceType);
}
catch (ResolutionFailedException)
{
return null;
}
}
[DebuggerStepThrough]
public IEnumerable<object> GetServices(Type serviceType)
{
try
{
return container.ResolveAll(serviceType);
}
catch (ResolutionFailedException)
{
return new List<object>();
}
}
public IDependencyScope BeginScope()
{
var child = container.CreateChildContainer();
return new UnityResolver(child);
}
public void Dispose()
{
container.Dispose();
}
}
}
WebApiConfig.cs:
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
//config.DependencyResolver = new NinjectResolver();
var container = new UnityContainer();
container.RegisterType<ILoginBusinessService, LoginBusinessService>(new HierarchicalLifetimeManager());
container.RegisterType<IUserBusinessService, UserBusinessService>(new HierarchicalLifetimeManager());
config.DependencyResolver = new UnityResolver(container);
//DependencyResolver.SetResolver(new UnityDependencyResolver(container));
config.MapHttpAttributeRoutes();
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{action}/{id}",
defaults: new { id = RouteParameter.Optional }
);
}
}
无法确定问题出在哪里?请输入代码并告诉我。
我已关注以下所有链接
确保控制器具有无参数公共构造函数? https://stackoverflow.com/questions/30435473/make-sure-that-the-controller-has-a-parameterless-public-constructor
Autofac - 确保控制器具有无参数公共构造函数 https://stackoverflow.com/questions/37542075/autofac-make-sure-that-the-controller-has-a-parameterless-public-constructor
使用 Ninject 确保控制器具有无参数公共构造函数 https://stackoverflow.com/questions/35834562/make-sure-that-the-controller-has-a-parameterless-public-constructor-using-ninje
确保控制器存在无参数公共构造函数错误 https://stackoverflow.com/questions/24254189/make-sure-that-the-controller-has-a-parameterless-public-constructor-error
但这些都没有解决我的问题。