帮忙.....找不到类型或命名空间名称 问题......

using System;
using
using System.Collections;
using
using System.Data;
using System.Data.OleDb;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using shop;

namespace shop
{
    /// <summary>
    /// Question 的摘要说明。
    /// </summary>
    public class Question : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.DataGrid dgList;
        
        public ConfigDetails con=new ConfigDetails();
    
        QuestionDB qDB = new QuestionDB();///Question.aspx.cs(26): 找不到类型或命名空间名称“QuestionDB”(是否缺少 using 指令或程序集引用？)到这里就运行不了

        private void Page_Load(object sender, System.EventArgs e)
        {
            // 在此处放置用户代码以初始化页面
            ConDB conDB = new ConDB();
            con  = conDB.GetSystemCon();

            if(!IsPostBack)
            {
                Bind();
            }
        }

        private void Bind()
        {
            this.dgList.DataSource = qDB.GetDSQuestions();
            this.dgList.DataBind();
        }

        #region Web 窗体设计器生成的代码
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: 该调用是 Web 窗体设计器所必需的。
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {   
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        
        private void dgList_DeleteCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
        {
            qDB.DeleteQuestion(int.Parse(this.dgList.DataKeys[e.Item.ItemIndex].ToString()));
            Bind();
        }

        private void dgList_PageIndexChanged(object source, System.Web.UI.WebControls.DataGridPageChangedEventArgs e)
        {
            this.dgList.CurrentPageIndex = e.NewPageIndex;
            Bind();
        }
    }
}