C#学习教程：类型”未映射分享

我一直试图解决这个错误一段时间了。

每当我的应用程序尝试创建数据上下文的实例时，我都会收到此错误。

以下是代码：

using System; using System.Collections.Generic; using System.Linq; using System.Web; using RandomRentals.Models; using System.Data.Entity; namespace RandomRentals.Models { public class RentalContext : DbContext { public DbSet Rentals { get; set; } public DbSet Categories { get; set; } public DbSet Items { get; set; } public DbSet Billings { get; set; } public DbSet Users { get; set; } public DbSet 

这是堆栈跟踪：

 [InvalidOperationException: The type 'RandomRentals.Rental' was not mapped. Check that the type has not been explicitly excluded by using the Ignore method or NotMappedAttribute data annotation. Verify that the type was defined as a class, is not primitive, nested or generic, and does not inherit from EntityObject.] System.Data.Entity.Internal.DbSetDiscoveryService.GetSets() +706 System.Data.Entity.Internal.DbSetDiscoveryService.InitializeSets() +31 System.Data.Entity.DbContext.DiscoverAndInitializeSets() +56 System.Data.Entity.DbContext.InitializeLazyInternalContext(IInternalConnection internalConnection, DbCompiledModel model) +79 System.Data.Entity.DbContext..ctor() +99 RandomRentals.Models.RentalContext..ctor() +44 RandomRentals.Models.UserModel..ctor() in C:UsersnikkaDesktopRandomRentalsRandomRentalsModelsUserModel.cs:11 [TargetInvocationException: Exception has been thrown by the target of an invocation.] System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck) +0 System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache) +98 System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean skipCheckThis, Boolean fillCache) +241 System.Activator.CreateInstance(Type type, Boolean nonPublic) +69 System.Web.Mvc.DefaultModelBinder.CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType) +199 System.Web.Mvc.DefaultModelBinder.BindComplexModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +572 System.Web.Mvc.DefaultModelBinder.BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +449 System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +317 System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +117 System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +343 System.Web.Mvc.Controller.ExecuteCore() +116 System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +97 System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +10 System.Web.Mvc.c__DisplayClassb.b__5() +37 System.Web.Mvc.Async.c__DisplayClass1.b__0() +21 System.Web.Mvc.Async.c__DisplayClass8`1.b__7(IAsyncResult _) +12 System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62 System.Web.Mvc.c__DisplayClasse.b__d() +50 System.Web.Mvc.SecurityUtil.b__0(Action f) +7 System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +22 System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +60 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8970061 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184 

这是完整的错误文本：

未映射“RandomRentals.Rental”类型。 使用Ignore方法或NotMappedAttribute数据批注检查未明确排除类型。 validation类型是否已定义为类，不是原始类，嵌套类还是通用类，并且不从EntityObjectinheritance。

编辑：租赁类的代码。

 [EdmEntityTypeAttribute(NamespaceName="DevelopmentModel", Name="Rental")] [Serializable()] [DataContractAttribute(IsReference=true)] 

public partial class Rental：EntityObject {#region Factory Method

 /// 
 /// Create a new Rental object. /// 
 /// Initial value of the RentalID property. /// Initial value of the AgreedPrice property. /// Initial value of the RentedOn property. /// Initial value of the RentalDays property. /// Initial value of the Returned property. /// Initial value of the RentedBy property. /// Initial value of the ReturnedOn property. /// Initial value of the OwnerReviewed property. /// Initial value of the BillingID property. /// Initial value of the ItemID property. /// Initial value of the CategoryDescription property. /// Initial value of the Title property. public static Rental CreateRental(global::System.Int32 rentalID, global::System.Decimal agreedPrice, global::System.DateTime rentedOn, global::System.Int32 rentalDays, global::System.Boolean returned, global::System.Int32 rentedBy, global::System.DateTime returnedOn, global::System.Boolean ownerReviewed, global::System.Int32 billingID, global::System.Int32 itemID, global::System.String categoryDescription, global::System.String title) { Rental rental = new Rental(); rental.RentalID = rentalID; rental.AgreedPrice = agreedPrice; rental.RentedOn = rentedOn; rental.RentalDays = rentalDays; rental.Returned = returned; rental.RentedBy = rentedBy; rental.ReturnedOn = returnedOn; rental.OwnerReviewed = ownerReviewed; rental.BillingID = billingID; rental.ItemID = itemID; rental.CategoryDescription = categoryDescription; rental.Title = title; return rental; } #endregion #region Primitive Properties /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=true, IsNullable=false)] [DataMemberAttribute()] public global::System.Int32 RentalID { get { return _RentalID; } set { if (_RentalID != value) { OnRentalIDChanging(value); ReportPropertyChanging("RentalID"); _RentalID = StructuralObject.SetValidValue(value); ReportPropertyChanged("RentalID"); OnRentalIDChanged(); } } } private global::System.Int32 _RentalID; partial void OnRentalIDChanging(global::System.Int32 value); partial void OnRentalIDChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)] [DataMemberAttribute()] public Nullable ProposedPrice { get { return _ProposedPrice; } set { OnProposedPriceChanging(value); ReportPropertyChanging("ProposedPrice"); _ProposedPrice = StructuralObject.SetValidValue(value); ReportPropertyChanged("ProposedPrice"); OnProposedPriceChanged(); } } private Nullable _ProposedPrice; partial void OnProposedPriceChanging(Nullable value); partial void OnProposedPriceChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.Decimal AgreedPrice { get { return _AgreedPrice; } set { OnAgreedPriceChanging(value); ReportPropertyChanging("AgreedPrice"); _AgreedPrice = StructuralObject.SetValidValue(value); ReportPropertyChanged("AgreedPrice"); OnAgreedPriceChanged(); } } private global::System.Decimal _AgreedPrice; partial void OnAgreedPriceChanging(global::System.Decimal value); partial void OnAgreedPriceChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.DateTime RentedOn { get { return _RentedOn; } set { OnRentedOnChanging(value); ReportPropertyChanging("RentedOn"); _RentedOn = StructuralObject.SetValidValue(value); ReportPropertyChanged("RentedOn"); OnRentedOnChanged(); } } private global::System.DateTime _RentedOn; partial void OnRentedOnChanging(global::System.DateTime value); partial void OnRentedOnChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.Int32 RentalDays { get { return _RentalDays; } set { OnRentalDaysChanging(value); ReportPropertyChanging("RentalDays"); _RentalDays = StructuralObject.SetValidValue(value); ReportPropertyChanged("RentalDays"); OnRentalDaysChanged(); } } private global::System.Int32 _RentalDays; partial void OnRentalDaysChanging(global::System.Int32 value); partial void OnRentalDaysChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.Boolean Returned { get { return _Returned; } set { OnReturnedChanging(value); ReportPropertyChanging("Returned"); _Returned = StructuralObject.SetValidValue(value); ReportPropertyChanged("Returned"); OnReturnedChanged(); } } private global::System.Boolean _Returned; partial void OnReturnedChanging(global::System.Boolean value); partial void OnReturnedChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.Int32 RentedBy { get { return _RentedBy; } set { OnRentedByChanging(value); ReportPropertyChanging("RentedBy"); _RentedBy = StructuralObject.SetValidValue(value); ReportPropertyChanged("RentedBy"); OnRentedByChanged(); } } private global::System.Int32 _RentedBy; partial void OnRentedByChanging(global::System.Int32 value); partial void OnRentedByChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.DateTime ReturnedOn { get { return _ReturnedOn; } set { OnReturnedOnChanging(value); ReportPropertyChanging("ReturnedOn"); _ReturnedOn = StructuralObject.SetValidValue(value); ReportPropertyChanged("ReturnedOn"); OnReturnedOnChanged(); } } private global::System.DateTime _ReturnedOn; partial void OnReturnedOnChanging(global::System.DateTime value); partial void OnReturnedOnChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.Boolean OwnerReviewed { get { return _OwnerReviewed; } set { OnOwnerReviewedChanging(value); ReportPropertyChanging("OwnerReviewed"); _OwnerReviewed = StructuralObject.SetValidValue(value); ReportPropertyChanged("OwnerReviewed"); OnOwnerReviewedChanged(); } } private global::System.Boolean _OwnerReviewed; partial void OnOwnerReviewedChanging(global::System.Boolean value); partial void OnOwnerReviewedChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)] [DataMemberAttribute()] public global::System.String RenterFeedback { get { return _RenterFeedback; } set { OnRenterFeedbackChanging(value); ReportPropertyChanging("RenterFeedback"); _RenterFeedback = StructuralObject.SetValidValue(value, true); ReportPropertyChanged("RenterFeedback"); OnRenterFeedbackChanged(); } } private global::System.String _RenterFeedback; partial void OnRenterFeedbackChanging(global::System.String value); partial void OnRenterFeedbackChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.Int32 BillingID { get { return _BillingID; } set { OnBillingIDChanging(value); ReportPropertyChanging("BillingID"); _BillingID = StructuralObject.SetValidValue(value); ReportPropertyChanged("BillingID"); OnBillingIDChanged(); } } private global::System.Int32 _BillingID; partial void OnBillingIDChanging(global::System.Int32 value); partial void OnBillingIDChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.Int32 ItemID { get { return _ItemID; } set { OnItemIDChanging(value); ReportPropertyChanging("ItemID"); _ItemID = StructuralObject.SetValidValue(value); ReportPropertyChanged("ItemID"); OnItemIDChanged(); } } private global::System.Int32 _ItemID; partial void OnItemIDChanging(global::System.Int32 value); partial void OnItemIDChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.String CategoryDescription { get { return _CategoryDescription; } set { OnCategoryDescriptionChanging(value); ReportPropertyChanging("CategoryDescription"); _CategoryDescription = StructuralObject.SetValidValue(value, false); ReportPropertyChanged("CategoryDescription"); OnCategoryDescriptionChanged(); } } private global::System.String _CategoryDescription; partial void OnCategoryDescriptionChanging(global::System.String value); partial void OnCategoryDescriptionChanged(); /// 
 /// No Metadata Documentation available. /// 
 [EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)] [DataMemberAttribute()] public global::System.String Title { get { return _Title; } set { OnTitleChanging(value); ReportPropertyChanging("Title"); _Title = StructuralObject.SetValidValue(value, false); ReportPropertyChanged("Title"); OnTitleChanged(); } } private global::System.String _Title; partial void OnTitleChanging(global::System.String value); partial void OnTitleChanged(); #endregion } 

任何帮助将不胜感激

 public class ContentRepository: DbContext { public DbSet content_Templates { get; set; } public DbSet master_Templates { get; set; } public DbSet master_Content_Maps { get; set; } public ContentRepository() : base("name=MessagingSystemEntities") { }