Map generic EntityBase<TEntity> class with FluentNHibernate

问题

I have a base class for all my entity types which is like

public abstract class EntityBase<TEntityType> : IEntityBase where TEntityType : EntityBase<TEntityType>
    {
        private List<IBusinessRule> _brokenRules = new List<IBusinessRule>();

        private int? _hashCode;

        public int ID { private set; get; }

and in my mappings i would like to use table-per-class strategy but how to map this EntityBase class? I tryed public class EntityBaseMap:ClassMap but it doesnt work. So how could i map this class? The reason why I want that is I dont want to write the repetetive stuff with Id(c=c.ID).Not.Null .... etc but have it in one mapping class.

my mapping class look like this

public class EntityBaseMap : ClassMap<EntityBase<???>>

what should i insert instead of ???

Thanks

回答1:

In NHibernate you can't map a class with an open generic, such as EntityBase<TEntityType>. Unfortunately you'll have to define a mapping class for each of the entities:

public class MyEntityMap : ClassMap<EntityBase<MyEntity>>
{
    ...
}

回答2:

Still you can simplify the process via reflection by creating a generic mapping and then using runtime typing, instead of creating static types:

    private static void AddWeakReferenceMappings(FluentMappingsContainer container, Assembly assembly)
    {
        var genericMappingType = typeof (WeakReferenceMap<>);
        var entityTypes = assembly.GetTypes().Where(type => type.IsSubclassOf(typeof (Entity)));
        foreach (var enitityType in entityTypes)
        {
            var newType = genericMappingType.MakeGenericType(enitityType);
            container.Add(newType);
        }
    }

回答3:

As a workaround you could define a non-generic "Proxy" class that will be implemented by EntityBaseMap:

public abstract class EntityProxy:IEntityBase
{
  public virtual Int Id {get; set;}
  /* Shared properties/ repetitive mappings */
}

And mapping with

public class EntityProxyMap : ClassMap<EntityProxy>
{
  /* Mapping*/
}

So you will then be able to create the EntityBase by

public abstract class EntityBase<TEntityType> : EntityProxy where TEntityType : EntityBase<TEntityType>
{
  /* Your implementation */
}

And finally use a

public class YourSubclassMap : SubclassMap<EntityBase<YourSubclass>>
{
  /* Do any necessary sub-class mapping */
}

来源：https://stackoverflow.com/questions/9631384/map-generic-entitybasetentity-class-with-fluentnhibernate