[InvalidCastException: 无法将类型为([color=#FF0000]Can not cast [/color])“NHibernate.Collection.Generic.PersistentGenericSet`1[qianhu.dadi.model.Catalog]”的对象强制转换为类型([color=#FF0000]strongly into [/color])“System.Collections.Generic.IList`1[qianhu.dadi.model.Catalog]”。]
   (Object , Object[] , SetterCallback ) +210
   NHibernate.Bytecode.Lightweight.AccessOptimizer.SetPropertyValues(Object target, Object[] values) +42
   NHibernate.Tuple.Entity.PocoEntityTuplizer.SetPropertyValuesWithOptimizer(Object entity, Object[] values) +66

[PropertyAccessException: Invalid Cast (check your mapping for property type mismatches); setter of qianhu.dadi.model.Catalog]
   NHibernate.Tuple.Entity.PocoEntityTuplizer.SetPropertyValuesWithOptimizer(Object entity, Object[] values) +157
   NHibernate.Tuple.Entity.PocoEntityTuplizer.SetPropertyValues(Object entity, Object[] values) +82
   NHibernate.Persister.Entity.AbstractEntityPersister.SetPropertyValues(Object obj, Object[] values, EntityMode entityMode) +47
   NHibernate.Engine.TwoPhaseLoad.InitializeEntity(Object entity, Boolean readOnly, ISessionImplementor session, PreLoadEvent preLoadEvent, PostLoadEvent postLoadEvent) +1012
   NHibernate.Loader.Loader.InitializeEntitiesAndCollections(IList hydratedObjects, Object resultSetId, ISessionImplementor session, Boolean readOnly) +390
   NHibernate.Loader.Loader.DoQuery(ISessionImplementor session, QueryParameters queryParameters, Boolean returnProxies) +958
   NHibernate.Loader.Loader.DoQueryAndInitializeNonLazyCollections(ISessionImplementor session, QueryParameters queryParameters, Boolean returnProxies) +94
   NHibernate.Loader.Loader.DoList(ISessionImplementor session, QueryParameters queryParameters) +167
   NHibernate.Loader.Loader.ListIgnoreQueryCache(ISessionImplementor session, QueryParameters queryParameters) +38
   NHibernate.Loader.Loader.List(ISessionImplementor session, QueryParameters queryParameters, ISet`1 querySpaces, IType[] resultTypes) +130
   NHibernate.Loader.Criteria.CriteriaLoader.List(ISessionImplementor session) +58
   NHibernate.Impl.SessionImpl.List(CriteriaImpl criteria, IList results) +541
   NHibernate.Impl.CriteriaImpl.List(IList results) +62
   NHibernate.Impl.CriteriaImpl.List() +87
   qianhu.dadi.dal.CatalogDal.checkExistsByName(String name) in G:\website\qianhu\dadi\dadiLib\dal\CatalogDal.cs:65
   qianhu.dadi.service.CatalogService.checkExistsByName(String name) in G:\website\qianhu\dadi\dadiLib\service\CatalogService.cs:34
   forum_addCatalog1.Button1_Click(Object sender, EventArgs e) in g:\website\qianhu\dadi\dadiSite\forum\addCatalog1.aspx.cs:28
   System.Web.UI.WebControls.Button.OnClick(EventArgs e) +96
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +116
   System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +31
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +32
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +72
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3824

using System;
using System.Collections.Generic;
using System.Text;

namespace qianhu.dadi.model
{
    public class Catalog
    {
        /// <summary>
        /// 编号
        /// </summary>
        private int cid;

        public virtual int Cid
        {
            get { return cid; }
            set { cid = value; }
        }
        /// <summary>
        /// 分类名
        /// </summary>
        private String name;

        public virtual String Name
        {
            get { return name; }
            set { name = value; }
        }
        /// <summary>
        /// 父分类
        /// </summary>
        private Catalog parent;

        public virtual Catalog Parent
        {
            get { return parent; }
            set { parent = value; }
        }

        /// <summary>
        /// 子分类
        /// </summary>
        private IList<Catalog> children;

        public virtual IList<Catalog> Children
        {
            get { return children; }
            set { children = value; }
        }



        /// <summary>
        /// 分类
        /// </summary>
        public Catalog()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }


        private IList<Message> messages;

        public virtual IList<Message> Messages
        {
            get { return messages; }
            set { messages = value; }
        }


    }
}

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
    namespace="qianhu.dadi.model" assembly="qianhu.dadi">

  <class name="Catalog" table="dadi_Catalog">
    <id name="Cid">
      <column name="Cid" not-null="true"/>
      <generator class="identity" />
    </id>

    <property name="Name" type="String"/>

    <many-to-one name="Parent" class="Catalog" column="Parent_ID" lazy="false" not-null="false" />

    <set name="Children" inverse="true" lazy="false">
      <key column="Parent_ID"/>
      <one-to-many class="Catalog"/>
    </set>

    <set name="Messages" inverse="true" lazy="false">
      <key column="Cid"/>
      <one-to-many class="Message"/>
    </set>


  </class>

</hibernate-mapping>

        public bool checkExistsByName(string name)
        {
            ISession session = NHibernateHelper.GetCurrentSession();
            IList<Catalog> catalogs = session.CreateCriteria<Catalog>().Add(Restrictions.Like("Name", name)).List<Catalog>();
            NHibernateHelper.CloseSession();
            if (catalogs.Count > 0)
            {
                return true;
            }
            else {
                return false;
            }
           
        }

private ICollection<Catalog> children;