protected void ImportTo_Excel_Click(object sender, EventArgs e)
        {
            //DataTable dt = null;
            //Response.ContentType = "application/vnd.ms-excel";
            //Response.AddHeader("Content-Disposition", "attachment;filename=" +
            //    Server.UrlEncode(this.Page.Title) + "_" + System.DateTime.Now.ToString("yyMMdd_fff") + ".xls");
            //Response.Charset = "GB2312";
            //Response.ContentEncoding = Encoding.GetEncoding("GB2312");
            //Response.Write(App_Code.Util.GetExcelString(dt));
            //Response.End();


            string connectionString = @"Data Source=192.168.0.20;Initial Catalog=Basedb;User ID=sa;Password=123456;Replication=True";
            try
            {
                SqlConnection cn = new SqlConnection(connectionString);
                cn.Open();
                try
                {
                    string s = "select * from Inv_ItemSell ";
                    SqlCommand cmd = new SqlCommand(s, cn);
                    SqlDataReader dr = cmd.ExecuteReader();
                    Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();
                    if (xlApp == null)
                    {
                    }
                    xlApp.Application.Workbooks.Add(true);
                    int row = 2, fieldcount;
                    fieldcount = dr.FieldCount;
                    for (int col = 0; col < fieldcount; col++)
                    {
                        xlApp.Cells[1, col + 1] = dr.GetName(col);
                    }
                    while (dr.Read())
                    {
                        for (int col = 0; col < fieldcount; col++)
                        {
                            xlApp.Cells[row, col + 1] = dr.GetValue(col).ToString();
                        }
                        row++;
                    }
                    xlApp.Visible = true;

                    xlApp.Quit();
                    xlApp = null;
                    //System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp);
                    string GUIDstringfile = System.Guid.NewGuid().ToString() + ".xls";
                    xlApp.Save(GUIDstringfile);
                    System.IO.FileInfo file = new System.IO.FileInfo(GUIDstringfile);
                    Response.Clear();
                    Response.Charset = "GB2312";
                    Response.ContentEncoding = System.Text.Encoding.UTF8;
                    // 添加头信息，为"文件下载/另存为"对话框指定默认文件名 
                    Response.AddHeader("Content-Disposition", "attachment; filename=" + Server.UrlEncode(file.Name));
                    // 添加头信息，指定文件大小，让浏览器能够显示下载进度 
                    Response.AddHeader("Content-Length", file.Length.ToString());

                    // 指定返回的是一个不能被客户端读取的流，必须被下载 
                    Response.ContentType = "application/ms-excel";

                    // 把文件流发送到客户端 
                    Response.WriteFile(file.FullName);
                    // 停止页面的执行 

                    Response.End();


                }
                catch (Exception ex)
                {

                }
                finally
                {
                    cn.Close();
                }
            }
            catch (Exception ex)
            {
            }
            finally
            {

            }
        }