[Serializable] 
public class Map
{
      public string UserID { get; set; }
      public string UserGroup { get; set; }
}

[Serializable] 
public class UserInfo
{ 
      public string UserID { get; set; }
 
      public string CardWord { get; set; }
 
      public string UserName { get; set; }
 
      public string PassWord { get; set; }
 
      public string UserPicture { get; set; }
 
      public string UserMail { get; set; }
 
      public DateTime RegTime { get; set; }
 
      public string UserStatus { get; set; }
 }

<!--省略非必要代码-->
<resultMaps>
     <resultMap id="SelectAllUser" class="UserInfo">
        <result property="UserID" column="ID"/>
        <result property="CardWord" column="Card_Word"/>
        <result property="UserName" column="User_Name"/>
        <result property="PassWord" column="Pass_Word"/>
        <result property="UserPicture" column="User_Picture"/>
        <result property="UserMail" column="User_Mail"/>
        <result property="RegTime" column="Reg_Time"/>
        <result property="UserStatus" column="User_Status"/>
      </resultMap> 
  </resultMaps>
<!--省略非必要代码-->
 <statements>
<!--获取好友信息-->
    <select id="GetAllUserByID" resultMap="SelectAllUser" parameterClass="System.Collections.Generic.List">
      <![CDATA[select ID,Card_Word,User_Name,Pass_Word,User_Picture,User_Mail,Reg_Time,User_Status from userinfo where ID in
           <iterate conjunction="," open="(" close=")">
              #[].UserID#
           </iterate>
       ]]>
    </select>
  </statements>

List<Map> hashTable = new List<Map>();
List<Userinfo> userList = null;
userList = mapper.QueryForList<UserInfo>("GetAllUserByID", hashTable).ToList();