无法扩展未映射的类：实体(Cannot extend unmapped class: Entity)

 我有一个名为Entity的基类： 
 
public class Entity
{
    public int Id {get;set;}
}
 
 假设我有一个名为Customer的类： 
 
public class Customer : Entity
{
    public string Name {get;set;}
}
 
 现在，在NHibernate 3.3.1中使用基于约定的映射映射，我尝试以下方法： 
 
public static class DataHelper
{
    private static HbmMapping GetMappings()
    {
        var mapper = new CustomModelMapper(typeof(Entity));           

        return mapper.CompileMappingFor(
            typeof(DataHelper).Assembly.GetExportedTypes()
                .Where(x => x.IsSubclassOf(typeof(Entity))));
    }
}
 
 当我尝试运行我的应用程序时，我收到错误“无法扩展未映射的类：实体”。 我不想映射Entity类 - 它只是继承一些常见属性的基类。 如何告诉NHibernate忽略未映射的类？ 作为参考，下面列出了我的CustomModelMapper类。 
 
 下面列出了我的CustomModelMapper类的代码以供参考 
 
internal class CustomModelMapper : ConventionModelMapper
{
    private const int DEFAULT_STRING_LENGTH = 100;
    private Type baseType;

    public CustomModelMapper(Type baseType)
    {
        this.baseType = baseType;
    }

    public CustomModelMapper()
    {
        SetupInspectors();
    }

    protected override void AppendDefaultEvents()
    {
        base.AppendDefaultEvents();
        BeforeMapClass += OnBeforeMapClass;
        BeforeMapProperty += OnBeforeMapProperty;
        BeforeMapManyToOne += OnBeforeMapManyToOne;
        BeforeMapBag += OnBeforeMapBag;
        BeforeMapList += OnBeforeMapList;
        BeforeMapSet += OnBeforeMapSet;
    }

    protected void OnBeforeMapClass(IModelInspector modelInspector, Type type, IClassAttributesMapper classCustomizer)
    {
        classCustomizer.Id(type.GetProperty("Id"), m => m.Generator(Generators.Native));
    }

    protected void OnBeforeMapProperty(IModelInspector modelInspector, PropertyPath member, IPropertyMapper propertyCustomizer)
    {
        if (member.LocalMember.GetPropertyOrFieldType().IsEnum)
        {
            var type = member.LocalMember.GetPropertyOrFieldType();
            var genericType = typeof(EnumStringType<>).MakeGenericType(type);
            propertyCustomizer.Type(genericType, null);
        }

        if (member.LocalMember.GetPropertyOrFieldType() == typeof(string))
            propertyCustomizer.Length(DEFAULT_STRING_LENGTH);
    }

    protected void OnBeforeMapManyToOne(IModelInspector modelInspector, PropertyPath member, IManyToOneMapper propertyCustomizer)
    {
        propertyCustomizer.Cascade(Cascade.All);
        propertyCustomizer.Fetch(FetchKind.Join);
        propertyCustomizer.Lazy(LazyRelation.NoLazy);

        propertyCustomizer.Index(string.Format("IX{0}{1}",
            member.GetContainerEntity(modelInspector).Name,
            member.LocalMember.Name));
    }

    protected void OnBeforeMapBag(IModelInspector modelInspector, PropertyPath member, IBagPropertiesMapper propertyCustomizer)
    {
        propertyCustomizer.Cascade(Cascade.All);
        propertyCustomizer.Lazy(CollectionLazy.Extra);
        propertyCustomizer.Fetch(CollectionFetchMode.Subselect);
    }

    protected void OnBeforeMapList(IModelInspector modelInspector, PropertyPath member, IListPropertiesMapper propertyCustomizer)
    {
        propertyCustomizer.Cascade(Cascade.All);
        propertyCustomizer.Lazy(CollectionLazy.Extra);
        propertyCustomizer.Fetch(CollectionFetchMode.Subselect);
    }

    protected void OnBeforeMapSet(IModelInspector modelInspector, PropertyPath member, ISetPropertiesMapper propertyCustomizer)
    {
        propertyCustomizer.Cascade(Cascade.All);
        propertyCustomizer.Lazy(CollectionLazy.Extra);
        propertyCustomizer.Fetch(CollectionFetchMode.Subselect);
    }

    protected void SetupInspectors()
    {
        IsRootEntity((type, declared) =>
        {
            return baseType.Equals(type.BaseType);
        });

        IsEntity((type, declared) =>
        {
            return baseType.IsAssignableFrom(type) && !type.IsInterface;
        });

        IsVersion((member, declared) =>
        {
            return
                member.Name == "Version" &&
                member.MemberType == MemberTypes.Property &&
                member.GetPropertyOrFieldType() == typeof(int);
        });


        IsBag((member, declared) =>
        {
            if (member.GetPropertyOrFieldType().IsGenericType)
                return IsGenericType(member, typeof(ICollection<>));

            return false;
        });

        IsList((member, declared) =>
        {
            if (member.GetPropertyOrFieldType().IsGenericType)
                return IsGenericType(member, typeof(IList<>));

            return false;
        });

        IsSet((member, declared) =>
        {
            if (member.GetPropertyOrFieldType().IsGenericType)
                return IsGenericType(member, typeof(ICG.ISet<>));

            return false;
        });
    }

    protected static bool IsGenericType(MemberInfo member, Type targetType)
    {
        var type = member.GetPropertyOrFieldType();
        var generics = type.GetGenericInterfaceTypeDefinitions();
        return generics.Contains(targetType);
    }
}

I have a base class called Entity:
 
public class Entity
{
    public int Id {get;set;}
}
 
Let's say I have a class called Customer:
 
public class Customer : Entity
{
    public string Name {get;set;}
}
 
Now, using convention based mapping by code in NHibernate 3.3.1, I try the following:
 
public static class DataHelper
{
    private static HbmMapping GetMappings()
    {
        var mapper = new CustomModelMapper(typeof(Entity));           

        return mapper.CompileMappingFor(
            typeof(DataHelper).Assembly.GetExportedTypes()
                .Where(x => x.IsSubclassOf(typeof(Entity))));
    }
}
 
When I try to run my app, I get the error "Cannot extend unmapped class: Entity". I don't want to map the Entity class - it's just a base class for inheriting some common properties. How can I tell NHibernate to ignore the unmapped class? For reference, my CustomModelMapper class is listed below. 
 
The code for my CustomModelMapper class is listed below for reference 
 
internal class CustomModelMapper : ConventionModelMapper
{
    private const int DEFAULT_STRING_LENGTH = 100;
    private Type baseType;

    public CustomModelMapper(Type baseType)
    {
        this.baseType = baseType;
    }

    public CustomModelMapper()
    {
        SetupInspectors();
    }

    protected override void AppendDefaultEvents()
    {
        base.AppendDefaultEvents();
        BeforeMapClass += OnBeforeMapClass;
        BeforeMapProperty += OnBeforeMapProperty;
        BeforeMapManyToOne += OnBeforeMapManyToOne;
        BeforeMapBag += OnBeforeMapBag;
        BeforeMapList += OnBeforeMapList;
        BeforeMapSet += OnBeforeMapSet;
    }

    protected void OnBeforeMapClass(IModelInspector modelInspector, Type type, IClassAttributesMapper classCustomizer)
    {
        classCustomizer.Id(type.GetProperty("Id"), m => m.Generator(Generators.Native));
    }

    protected void OnBeforeMapProperty(IModelInspector modelInspector, PropertyPath member, IPropertyMapper propertyCustomizer)
    {
        if (member.LocalMember.GetPropertyOrFieldType().IsEnum)
        {
            var type = member.LocalMember.GetPropertyOrFieldType();
            var genericType = typeof(EnumStringType<>).MakeGenericType(type);
            propertyCustomizer.Type(genericType, null);
        }

        if (member.LocalMember.GetPropertyOrFieldType() == typeof(string))
            propertyCustomizer.Length(DEFAULT_STRING_LENGTH);
    }

    protected void OnBeforeMapManyToOne(IModelInspector modelInspector, PropertyPath member, IManyToOneMapper propertyCustomizer)
    {
        propertyCustomizer.Cascade(Cascade.All);
        propertyCustomizer.Fetch(FetchKind.Join);
        propertyCustomizer.Lazy(LazyRelation.NoLazy);

        propertyCustomizer.Index(string.Format("IX{0}{1}",
            member.GetContainerEntity(modelInspector).Name,
            member.LocalMember.Name));
    }

    protected void OnBeforeMapBag(IModelInspector modelInspector, PropertyPath member, IBagPropertiesMapper propertyCustomizer)
    {
        propertyCustomizer.Cascade(Cascade.All);
        propertyCustomizer.Lazy(CollectionLazy.Extra);
        propertyCustomizer.Fetch(CollectionFetchMode.Subselect);
    }

    protected void OnBeforeMapList(IModelInspector modelInspector, PropertyPath member, IListPropertiesMapper propertyCustomizer)
    {
        propertyCustomizer.Cascade(Cascade.All);
        propertyCustomizer.Lazy(CollectionLazy.Extra);
        propertyCustomizer.Fetch(CollectionFetchMode.Subselect);
    }

    protected void OnBeforeMapSet(IModelInspector modelInspector, PropertyPath member, ISetPropertiesMapper propertyCustomizer)
    {
        propertyCustomizer.Cascade(Cascade.All);
        propertyCustomizer.Lazy(CollectionLazy.Extra);
        propertyCustomizer.Fetch(CollectionFetchMode.Subselect);
    }

    protected void SetupInspectors()
    {
        IsRootEntity((type, declared) =>
        {
            return baseType.Equals(type.BaseType);
        });

        IsEntity((type, declared) =>
        {
            return baseType.IsAssignableFrom(type) && !type.IsInterface;
        });

        IsVersion((member, declared) =>
        {
            return
                member.Name == "Version" &&
                member.MemberType == MemberTypes.Property &&
                member.GetPropertyOrFieldType() == typeof(int);
        });


        IsBag((member, declared) =>
        {
            if (member.GetPropertyOrFieldType().IsGenericType)
                return IsGenericType(member, typeof(ICollection<>));

            return false;
        });

        IsList((member, declared) =>
        {
            if (member.GetPropertyOrFieldType().IsGenericType)
                return IsGenericType(member, typeof(IList<>));

            return false;
        });

        IsSet((member, declared) =>
        {
            if (member.GetPropertyOrFieldType().IsGenericType)
                return IsGenericType(member, typeof(ICG.ISet<>));

            return false;
        });
    }

    protected static bool IsGenericType(MemberInfo member, Type targetType)
    {
        var type = member.GetPropertyOrFieldType();
        var generics = type.GetGenericInterfaceTypeDefinitions();
        return generics.Contains(targetType);
    }
}

原文：https://stackoverflow.com/questions/11402502