在DataList中的ImageButton绑定了一个ID,如何获取该ID呢

Web层 
<asp:DataList ID="DataList1" runat="server"  RepeatColumns="2" RepeatDirection="Horizontal" DataKeyField="GoodsID" > 
                    <ItemTemplate> 
                        <div id="ny_order_bg"> 
        <div id="left_pic"> <a href="GoodsInfo.aspx?GoodsID= <%#Eval("GoodsID")%>"/> <img src=' <%#Eval("GoodsPic")%>' width="80" border="0"  alt="" /> </div> 
<div id="pic_info"> 
    <div id="info_tt"> <a href="GoodsInfo.aspx?GoodsID= <%#Eval("GoodsID")%>"/> <%#Eval("GoodsName")%> <br /> <%#Eval("EnglishName")%> </div> 
  <div id="info_nr">产品规格：酒精度 <%#Eval("SpecName")%>（V/V） <br />市场价： <span class="red"> <%#Eval("MarketPrice")%> </span>元/瓶 会员价： <span class="red"> <%#Eval("MemberPrice")%> </span>元/瓶 </div> 
<div id="info_bottom"> <asp:ImageButton ID="imgShoppingCart" runat="server" OnClick="imgShoppingCart_Click" ImageUrl="~/images/order.gif" CommandArgument=' <%#Eval("GoodsID")%>' /> <asp:HiddenField ID="GID" runat="server" /> </div> 
</div> 
  </div>                  
                    </ItemTemplate> 
                </asp:DataList> 
代码: 
protected void imgShoppingCart_Click(object sender, ImageClickEventArgs e) 
    { 
        if (Session["UID"] == null) 
        { 
            ControlControls(); 
          // Response.Write(" <script language=javascript>alert('对不起,你没有登陆,不能购买物品');window.location='Login.aspx' </script>"); 
        } 
        else 
        { 
            UID = int.Parse(Session["UID"].ToString()); 
            ShopCartClass sc = new ShopCartClass(); 
            ShopCartManage shopCartManage = new ShopCartManage(); 
            string ID = Request.QueryString["GoodsID"];//取不出值，为空 
            //gi = goodsInfoManage.SGoodInfo(int.Parse(ID)); 
            //sc.GoodsID = gi.GoodsID; 
            sc.SumPrice = decimal.Parse(Request.QueryString["SumPrice"]); 
            sc.UID = UID; 
          
            int result = shopCartManage.AddShopCart(sc); 
            if (result == 1) 
            {                 Response.Redirect("ShopCart.aspx"); 
            } 
            else 
            { 
                Response.Write(" <script type='text/javascript'>alert('操作失败！');history.back(); </script>"); 
            } 
        } 
    } 绑定的代码: 
    private void GridViewBind() 
    { 
        AspNetPager1.RecordCount = goodsInfoManage.InfoCount(gi); 
        DataList1.DataSource = goodsInfoManage.SGoodsInfo(AspNetPager1.CurrentPageIndex, AspNetPager1.PageSize); 
        DataList1.DataBind(); 
        
    } 存储过程： 
public List <GoodsInfo> SGoodsInfo(int pageIndex, int pageSize) 
        { 
            SqlParameter[] sqlParameters = { 
                new SqlParameter("@pageIndex",SqlDbType.Int), 
                new SqlParameter("@pageSize",SqlDbType.Int) 
            }; 
            sqlParameters[0].Value = pageIndex; 
            sqlParameters[1].Value = pageSize; 
            List <GoodsInfo> list = new List <GoodsInfo>(); 
            SqlDataReader reader = SqlHelper.ExecuteReader(SqlHelper.ConnectionString, CommandType.StoredProcedure, "User_SGoodsInfo", sqlParameters); 
            while (reader.Read()) 
            { 
                GoodsInfo gi = new GoodsInfo(); 
                gi.GoodsID = int.Parse(reader["GoodsID"].ToString()); 
                gi.GoodsName = reader["GoodsName"].ToString(); 
                gi.EnglishName = reader["EnglishName"].ToString(); 
                gi.SpecName = reader["TypeName"].ToString(); 
                gi.GoodsPic = reader["GoodsPic"].ToString(); 
                gi.MarketPrice = decimal.Parse(reader["MarketPrice"].ToString()); 
                gi.MemberPrice = decimal.Parse(reader["MemberPrice"].ToString()); 
                list.Add(gi); 
            } 
            reader.Dispose(); 
            return list; 
        } 
        public int InfoCount(GoodsInfo gi) 
        { 
            return Convert.ToInt32(SqlHelper.ExecuteScalar(SqlHelper.ConnectionString, CommandType.StoredProcedure, "proc_GetGoodsCount", null).ToString()); 
        }