在MVc5 Repo模式中没有为此对象定义无参数构造函数

Question

我有这个问题

没有为此对象定义的无参数构造函数。描述：执行当前Web请求期间发生未处理的异常。请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息。

异常详细信息：System.MissingMethodException：没有为此对象定义的无参数构造函数。

我在mvc中创建了一个新项目，并使用分层架构来处理数据和存储库。所以，当我打电话给帐户控制器我ZGit这个错误

这是我的代码： - 帐户控制器

public class AccountController : Controller
    {
        private readonly IAuthentication repositoryIAuthentication;
        private readonly IUserRepository repositoryUser;
        private readonly IPostRepository repositoryPost;
        private readonly ICommentRepository repositoryComment;
        private readonly ICategoryRepository repositoryCategory;
        private readonly MembershipProvider repositoryMemberShipProvider;
        private readonly IDEncryptionRepository repositoryDEncryption;
        private readonly IEmailSettingRepository repositoryEmailSetting;
        private readonly ISettingRepository repositorySetting;
        public AccountController(IUserRepository repoUser,
                                 IAuthentication repoIAuthentication,
                                 IPostRepository repoPost,
                                 ICommentRepository repoComment,
                                 ICategoryRepository repoCategory,
                                 MembershipProvider repoMemberShipProvider,
                                 IDEncryptionRepository repoDEncryption,
                                 IEmailSettingRepository repoEmailSetting,
                                 ISettingRepository repoSetting)
        {
            repositoryUser = repoUser;
            repositoryIAuthentication = repoIAuthentication;
            repositoryCategory = repoCategory;
            repositoryComment = repoComment;
            repositoryPost = repoPost;
            repositoryMemberShipProvider = repoMemberShipProvider;
            repositoryDEncryption = repoDEncryption;
            repositoryEmailSetting = repoEmailSetting;
            repositorySetting = repoSetting;
        }

这是页面上显示的详细错误： -

[MissingMethodException：没有为此对象定义无参数构造函数。] System.RuntimeTypeHandle.CreateInstance（RuntimeType类型，Boolean publicOnly，Boolean noCheck，Boolean＆canBeCached，RuntimeMethodHandleInternal＆ctor，Boolean＆bNeedSecurityCheck）+0 System.RuntimeType.CreateInstanceSlow（Boolean publicOnly，Boolean skipCheckThis，Boolean fillCache，StackCrawlMark＆stackMark）+119 System.RuntimeType.CreateInstanceDefaultCtor（Boolean publicOnly，Boolean skipCheckThis，Boolean fillCache，StackCrawlMark＆stackMark）+232 System.Activator.CreateInstance（Type type，Boolean nonPublic）+83 System.Activator.CreateInstance（Type type）+11 System.Web.Mvc .DefaultControllerActivator.Create（RequestContext requestContext，Type controllerType）+55

[InvalidOperationException：尝试创建“WebAppBlog.Controllers.AccountController”类型的控制器时发生错误。确保控制器具有无参数的公共构造函数。] System.Web.Mvc.DefaultControllerActivator.Create（RequestContext requestContext，Type controllerType）+178 System.Web.Mvc.DefaultControllerFactory.GetControllerInstance（RequestContext requestContext，Type controllerType）+76 System.Web.Mvc.DefaultControllerFactory.CreateController（RequestContext requestContext，String controllerName）+88 System.Web.Mvc.MvcHandler.ProcessRequestInit（HttpContextBase httpContext，IController＆controller，IControllerFactory＆factory）+194 System.Web.Mvc.MvcHandler.BeginProcessRequest（HttpContextBase httpContext，AsyncCallback callback，Object state）+50 System.Web.Mvc.MvcHandler.BeginProcessRequest（HttpContext httpContext，AsyncCallback回调，对象状态）+48 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest（HttpContext context，AsyncCallback cb，Object extraData）+16 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute（）+ 103 System.Web.HttpApplication.ExecuteStepImpl（IExecutionStep step）+48 System.Web.HttpApplication.ExecuteStep（IExecutionStep step，Boolean＆completedSynchronously）+159

Answer 1

我怀疑问题在于你的控制器拥有大量的依赖关系。其中一个存储库可能具有尚未在容器中注册的依赖项。

我将研究工作单元模式，如果使用实体框架，则使用它的dbcontext（实现工作单元模式）。或者甚至更好地抽象到IAccountService并在实现中使用工作单元模式。