比如表中三個字段
key1 int,key2 int,item varchar(50)
前面2個字段聯合主鍵

前台代碼：

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

後台代碼：

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 窗體設計器生成的代碼#region Web 窗體設計器生成的代碼
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: 該調用是 ASP.NET Web 窗體設計器所必需的。
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//// <summary>
        /// 設計器支持所需的方法 - 不要使用代碼編輯器修改
        /// 此方法的內容。
        /// </summary>
        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(); 
            }
        }
    }
}