using System;
using System.IO;
using NPOI.HSSF.UserModel;
using NPOI.HPSF;
using NPOI.SS.UserModel;

using ICSharpCode.SharpZipLib.Zip;

namespace NpoiAndZip
{
public partial class ExportDownloadExcel : System.Web.UI.Page
    {
protected void Page_Load(object sender, EventArgs e)
        {
        }

protected void btnOK_Click(object sender, EventArgs e)
        {
string filename = "test.zip";
            Response.ContentType = "application/zip";
            Response.AddHeader("Content-Disposition", string.Format("attachment;filename={0}", filename));
            Response.Clear();

            InitializeWorkbook();
            GenerateData();
            MemoryStream ms1 = new MemoryStream();
            MemoryStream ms2=new MemoryStream();
            MemoryStream ms3=new MemoryStream();
            ms1 = WriteToStream(hssfworkbook);
            ms2 = WriteToStream(hssfworkbook2);
            ms3 = WriteToStream(hssfworkbook3);
            MemoryStream st = new MemoryStream();
using (ZipFile zip = ZipFile.Create(st))
            {
                zip.BeginUpdate();
                StreamDataSource d1=new StreamDataSource(ms1);
                StreamDataSource d2 = new StreamDataSource(ms2);
                StreamDataSource d3 = new StreamDataSource(ms3);
//添加文件
                zip.Add(d1, "test1.xls");
                zip.Add(d2, "test2.xls");
                zip.Add(d3, "test3.xls");
                zip.CommitUpdate();
            }
            Response.BinaryWrite(st.GetBuffer());
            Response.End();
        }

        HSSFWorkbook hssfworkbook;
        HSSFWorkbook hssfworkbook2;
        HSSFWorkbook hssfworkbook3;
        MemoryStream WriteToStream(HSSFWorkbook workbook)
        {
//Write the stream data of workbook to the root directory
            MemoryStream file = new MemoryStream();
            workbook.Write(file);
return file;
        }

void GenerateData()
        {
            ISheet sheet1 = hssfworkbook.CreateSheet("Sheet1");
            ISheet sheet2 = hssfworkbook2.CreateSheet("Sheet1");
            ISheet sheet3 = hssfworkbook3.CreateSheet("Sheet1");
            sheet1.CreateRow(0).CreateCell(0).SetCellValue("This is a Sample");
            sheet2.CreateRow(0).CreateCell(0).SetCellValue("This is a Sample");
            sheet3.CreateRow(0).CreateCell(0).SetCellValue("This is a Sample");
int x = 1;
for (int i = 1; i <= 15; i++)
            {
                IRow row = sheet1.CreateRow(i);
for (int j = 0; j < 15; j++)
                {
                    row.CreateCell(j).SetCellValue(x++);
                }
            }
for (int i = 1; i <= 15; i++)
            {
                IRow row = sheet2.CreateRow(i);
for (int j = 0; j < 15; j++)
                {
                    row.CreateCell(j).SetCellValue(x++);
                }
            }
for (int i = 1; i <= 15; i++)
            {
                IRow row = sheet3.CreateRow(i);
for (int j = 0; j < 15; j++)
                {
                    row.CreateCell(j).SetCellValue(x++);
                }
            }
        }

void InitializeWorkbook()
        {
            hssfworkbook = new HSSFWorkbook();
            hssfworkbook2 = new HSSFWorkbook();
            hssfworkbook3 = new HSSFWorkbook();
////create a entry of DocumentSummaryInformation
            DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
            dsi.Company = "NPOI Team";
            hssfworkbook.DocumentSummaryInformation = dsi;

////create a entry of SummaryInformation
            SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
            si.Subject = "NPOI SDK Example";
            hssfworkbook.SummaryInformation = si;

////create a entry of DocumentSummaryInformation
            DocumentSummaryInformation dsi2 = PropertySetFactory.CreateDocumentSummaryInformation();
            dsi2.Company = "NPOI Team";
            hssfworkbook2.DocumentSummaryInformation = dsi2;

////create a entry of SummaryInformation
            SummaryInformation si2 = PropertySetFactory.CreateSummaryInformation();
            si2.Subject = "NPOI SDK Example";
            hssfworkbook2.SummaryInformation = si2;

////create a entry of DocumentSummaryInformation
            DocumentSummaryInformation dsi3 = PropertySetFactory.CreateDocumentSummaryInformation();
            dsi3.Company = "NPOI Team";
            hssfworkbook3.DocumentSummaryInformation = dsi3;

////create a entry of SummaryInformation
            SummaryInformation si3 = PropertySetFactory.CreateSummaryInformation();
            si3.Subject = "NPOI SDK Example";
            hssfworkbook3.SummaryInformation = si3;
        }
    }

    //只有实现IStaticDataSource接口才能实现流操作
class StreamDataSource : IStaticDataSource
    {
public byte[] bytes { get; set; }
public StreamDataSource(MemoryStream ms)
        {
            bytes = ms.GetBuffer();
        }

public Stream GetSource()
        {
            Stream s = new MemoryStream(bytes);
return s;
        }
    }
}