联合主键的情况怎么在DataGrid中利用DataKeys定位记录

比如表中三个字段
key1 int,key2 int,item varchar(50)
前面2个字段联合主键

前台代码：

< asp:DataGrid  id ="DataGrid1"  runat ="server"  AutoGenerateColumns ="False"  DataKeyField ="DoubleKey" >
                 < Columns >
                     < asp:BoundColumn  DataField ="item"  HeaderText ="item" > asp:BoundColumn >
                     < asp:ButtonColumn  CommandName ="del"  Text ="删除" > asp:ButtonColumn >
                 Columns >
             asp:DataGrid >

后台代码：

using  System;
using  System.Collections;
using  System.ComponentModel;
using  System.Data;
using  System.Data.SqlClient;
using  System.Drawing;
using  System.Web;
using  System.Web.SessionState;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.Web.UI.HtmlControls;

namespace  csdn2
{
    public class WebForm20 : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.DataGrid DataGrid1;
    
        private void Page_Load(object sender, System.EventArgs e)
        {
            if(!IsPostBack)
            {
                SetBind();
            }
        }
        private void SetBind()
        {
            SqlConnection conn=new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["conn"]);
            SqlDataAdapter da=new SqlDataAdapter("select * from doublekey",conn);
            DataSet ds=new DataSet();
            da.Fill(ds);
            DataTable dt=ds.Tables[0];
            DataColumn dc=new DataColumn("DoubleKey",typeof(string),"key1+'#'+key2");
            dt.Columns.Add(dc);
            this.DataGrid1.DataSource=dt;
            this.DataGrid1.DataBind();
        }
        Web 窗体设计器生成的代码#region Web 窗体设计器生成的代码
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//// 

        /// 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。
        /// 

        private void InitializeComponent()
        {    
            this.DataGrid1.ItemCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_ItemCommand);
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        private void DataGrid1_ItemCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
        {
            if(e.CommandName=="del")
            {
                SqlConnection conn=new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["conn"]); 
                SqlCommand comm=new SqlCommand("delete from doublekey where key1=@key1 and key2=@key2",conn); 
                SqlParameter parm1=new SqlParameter("@key1",SqlDbType.Int);
                SqlParameter parm2=new SqlParameter("@key2",SqlDbType.Int); 
                string [] keys=this.DataGrid1.DataKeys[e.Item.ItemIndex].ToString().Split('#');
                parm1.Value=keys[0];
                parm2.Value=keys[1];
                comm.Parameters.Add(parm1);
                comm.Parameters.Add(parm2); 
                conn.Open(); 
                comm.ExecuteNonQuery(); 
                conn.Close(); 
                SetBind(); 
            }
        }
    }
}