Fluent NHibernate 如何重写抽象基类的映射

Question

我想对我的所有 Types Of AuditedEntity 执行此操作，但正如我们告诉 FH 忽略基本摘要一样，代码不会受到影响。我不想对我的所有实体执行此操作，然后让某人在添加新的 typeof

public abstract class AuditedEntity : Entity ...

public class AuditedEntityMappings : IAutoMappingOverride<AuditedEntity>
  {
    public void Override(AutoMapping<AuditedEntity> mapping)
    {
      mapping.Where("DeletedById is null");
    }
  }

这篇文章看起来很有希望，但该方法已被弃用

Answer 1

感谢对一些相当复杂的表达式的一些帮助，导致了以下扩展：

var model = 
  AutoMap.AssemblyOf<AuditedEntity>(new AutomappingConfiguration(databaseName))
   .HideDeletedEntities();

...

public static class ReflectiveEnumerator
  {
    public static IEnumerable<Type> GetSubTypesOf<T>() where T : class
    {
      return Assembly.GetAssembly(typeof (T)).GetTypes()
        .Where(myType => myType.IsClass && 
          !myType.IsAbstract && 
          myType.IsSubclassOf(typeof (T)));
    }
  }

  public static class AutoPersistenceModelExtensions
  {
    public static AutoPersistenceModel HideDeletedEntities(this AutoPersistenceModel model)
    {
      var types = ReflectiveEnumerator.GetSubTypesOf<AuditedEntity>();

      foreach (var t in types)
      {
        var mapped = typeof(AutoMapping<>).MakeGenericType(t);

        var p = Expression.Parameter(mapped, "m");
        var expression = Expression.Lambda(Expression.GetActionType(mapped),
                                           Expression.Call(p, mapped.GetMethod("Where"),
                                                           Expression.Constant("DeletedById is null")), p);

        typeof(AutoPersistenceModel).GetMethod("Override").MakeGenericMethod(t)
          .Invoke(model, new object[] { expression.Compile() });
      }
      return model;
    }
  }