InsertIntoExcelEx

 private bool InsertIntoExcelEx(System.Data.DataTable dt)
    {
        string baseFileName = "SignCustomers";

        string mPath = System.IO.Path.GetTempPath() + System.IO.Path.GetTempFileName().Replace(".tmp", "") + ".xls";
        mPath = Server.MapPath("~/Temp") + "\\" + baseFileName + "JJLTemp.xls";

        System.IO.File.Copy(Server.MapPath("~/Temp") + "\\" + baseFileName + "JJL.xls", Server.MapPath("~/Temp") + "\\" + baseFileName + "JJLTemp.xls", true);

        string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + mPath + ";" + "Extended Properties=Excel 5.0;";
        string strExcel = "insert into [签约客户$] (区域公司,部门,项目部,咨询,客户姓名,合同号,状态,签约日期,电话,籍贯,出生日期,媒体来源,注册方式) values('{0}','{1}','{2}','{3}','{4}','{5}','{6}','{7}','{8}','{9}','{10}','{11}','{12}')";

        bool isSuccessful = false;
        string tempID = "";
        try
        {
            using (OleDbConnection conn = new OleDbConnection(strConn))
            {
                conn.Open();
                foreach (DataRow row in dt.Rows)
                {
                    string appdate = "";
                    string sql = string.Format(strExcel, row["区域"], row["部门"], row["项目部"], row["咨询"]
                        , row["客户姓名"], row["合同号"], row["状态"], !string.IsNullOrEmpty(row["签约日期"].ToString()) ? DateTime.Parse(row["签约日期"].ToString()).ToString("yyyy-MM-dd") : "", row["电话"], row["籍贯"], !string.IsNullOrEmpty(row["出生日期"].ToString()) ? DateTime.Parse(row["出生日期"].ToString()).ToString("yyyy-MM-dd") : "", row["媒体来源"], row["注册方式"]);
                    tempID = sql;
                    try
                    {
                        OleDbCommand cmd = new OleDbCommand(sql, conn);
                        int num = cmd.ExecuteNonQuery();
                        if (num == 1)
                        {
                            isSuccessful = true;
                        }
                    }
                    catch (Exception ex)
                    {

                        string kk = "";
                    }
                }
                conn.Close();
            }
        }
        catch (Exception erorr)
        {
            throw;
        }
        Random r=new Random();
        int rand = r.Next(10000, 99999);
        string str = DateTime.Now.ToString("yyyyMMddHHmmssff") + rand.ToString();
        string fileName = "JJL(" + str + ")";
        Response.Clear();

        Response.Buffer = true;
        Response.Charset = "GB2312";
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");

        Response.AppendHeader("Content-Disposition", "attachment;filename=" + fileName + ".xls");
        this.Response.ContentType = "Accept-Encoding: x-compress; x-zip";

        System.IO.FileStream fs = new FileStream(Server.MapPath("~/Temp") + "\\" + baseFileName + "JJLTemp.xls", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.Delete);
        byte[] buffer = new byte[fs.Length];
        fs.Read(buffer, 0, (int)fs.Length);
        fs.Close();

        if (buffer != null)
        {
            Response.BinaryWrite(buffer);
        }
        Response.Flush();
        Response.Close();
        return isSuccessful;
    }