。。。
              if (toMappingName.ToUpper() == fromMappingName.ToUpper())
                    {
                        if (toProperty.GetSetMethod() != null 
                            && fromProperty.CanRead
                            && toProperty.CanWrite)
                        {
                            var fromValue = fromProperty.GetValue(fromEntity, null);
                            if (fromValue == null)
                                try { toProperty.SetValue(toEntity, null, null); } //这句内部引发异常
                                catch { }
                            else
                                toProperty.SetValue(toEntity, fromValue, null);
                            break;
                        }
                    }
。。。



这句是上面引发异常那句的内部代码：
/// <summary>
        /// 没有元数据文档可用。
        /// </summary>
        [XmlIgnoreAttribute()]
        [SoapIgnoreAttribute()]
        [DataMemberAttribute()]
        [EdmRelationshipNavigationPropertyAttribute("ContentManagementModel", "FK_CM_AdminUser_CM_AdminAnswer1", "CM_AdminAnswer")]
        public CM_AdminAnswer CM_AdminAnswer
        {
            get
            {
                return ((IEntityWithRelationships)this).RelationshipManager.GetRelatedReference<CM_AdminAnswer>("ContentManagementModel.FK_CM_AdminUser_CM_AdminAnswer1", "CM_AdminAnswer").Value;
            }
            set
            {
                ((IEntityWithRelationships)this).RelationshipManager.GetRelatedReference<CM_AdminAnswer>("ContentManagementModel.FK_CM_AdminUser_CM_AdminAnswer1", "CM_AdminAnswer").Value = value; //虽然上面那句加了try..catch，但异常还是在这里被直接抛出来了
            }


        }