Excel 的 DLL 生成 Excel 文档

 using System;

    
 using System.Collections.Generic;
    
 using System.Text;
    
 using System.Web;
    
 using System.IO;
    
 using PackingDetailModel = Supplier.Model.PackingDetailModel;
    
 using Microsoft.Office.Interop.Excel;
    
  
    
 namespace Supplier.Common
    
 {
    
     public class ExcelDLLHelper
    
     {
    
     private const string FORMAT = "@";
    
     private static string path = HttpContext.Current.Server.MapPath(@"~/Upload/Invoices/" + PageHelper.BillId() + ".xls");
    
  
    
     public static void GainOCExcel(HttpRequest request, HttpResponse r