ASP.NET使用NPOI类库导出Excel

/*
 * 作者: 牛腩
 * 创建时间: 2010-1-4 15:15:05
 * Email: [e-mail]
 * 说明: 导出EXCEL的类，使用说明见：http://msdn.microsoft.com/zh-tw/ee818993.aspx
 */

using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Web;
using NPOI;
using NPOI.HPSF;
using NPOI.HSSF;
using NPOI.HSSF.UserModel;
using NPOI.POIFS;
using NPOI.Util;

public class DataTableRenderToExcel
{
    public static Stream RenderDataTableToExcel(DataTable SourceTable)
    {
        HSSFWorkbook workbook = new HSSFWorkbook();
        MemoryStream ms = new MemoryStream();
        HSSFSheet sheet = workbook.CreateSheet();
        HSSFRow headerRow = sheet.CreateRow(0);

        // handling header.
        foreach (DataColumn column in SourceTable.Columns)
            headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);

        // handling value.
        int rowIndex = 1;

        foreach (DataRow row in SourceTable.Rows)
        {
            HSSFRow dataRow = sheet.CreateRow(rowIndex);

            foreach (DataColumn column in SourceTable.Columns)
            {
                dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
            }

            rowIndex++;
        }

        workbook.Write(ms);
        ms.Flush();
        ms.Position = 0;

        sheet = null;
        headerRow = null;
        workbook = null;

        return ms;
    }

    public static void RenderDataTableToExcel(DataTable SourceTable, string FileName)
    {
        MemoryStream ms = RenderDataTableToExcel(SourceTable) as MemoryStream;
        FileStream fs = new FileStream(FileName, FileMode.Create, FileAccess.Write);
        byte[] data = ms.ToArray();

        fs.Write(data, 0, data.Length);
        fs.Flush();
        fs.Close();

        data = null;
        ms = null;
        fs = null;
    }

    public static DataTable RenderDataTableFromExcel(Stream ExcelFileStream, string SheetName, int HeaderRowIndex)
    {
        HSSFWorkbook workbook = new HSSFWorkbook(ExcelFileStream);
        HSSFSheet sheet = workbook.GetSheet(SheetName);

        DataTable table = new DataTable();

        HSSFRow headerRow = sheet.GetRow(HeaderRowIndex);
        int cellCount = headerRow.LastCellNum;

        for (int i = headerRow.FirstCellNum; i < cellCount; i++)
        {
            DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
            table.Columns.Add(column);
        }

        int rowCount = sheet.LastRowNum;

        for (int i = (sheet.FirstRowNum + 1); i < sheet.LastRowNum; i++)
        {
            HSSFRow row = sheet.GetRow(i);
            DataRow dataRow = table.NewRow();

            for (int j = row.FirstCellNum; j < cellCount; j++)
                dataRow[j] = row.GetCell(j).ToString();
        }

        ExcelFileStream.Close();
        workbook = null;
        sheet = null;
        return table;
    }

    public static DataTable RenderDataTableFromExcel(Stream ExcelFileStream, int SheetIndex, int HeaderRowIndex)
    {
        HSSFWorkbook workbook = new HSSFWorkbook(ExcelFileStream);
        HSSFSheet sheet = workbook.GetSheetAt(SheetIndex);

        DataTable table = new DataTable();

        HSSFRow headerRow = sheet.GetRow(HeaderRowIndex);
        int cellCount = headerRow.LastCellNum;

        for (int i = headerRow.FirstCellNum; i < cellCount; i++)
        {
            DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
            table.Columns.Add(column);
        }

        int rowCount = sheet.LastRowNum;

        for (int i = (sheet.FirstRowNum + 1); i < sheet.LastRowNum; i++)
        {
            HSSFRow row = sheet.GetRow(i);
            DataRow dataRow = table.NewRow();

            for (int j = row.FirstCellNum; j < cellCount; j++)
            {
                if (row.GetCell(j) != null)
                    dataRow[j] = row.GetCell(j).ToString();
            }

            table.Rows.Add(dataRow);
        }

        ExcelFileStream.Close();
        workbook = null;
        sheet = null;
        return table;
    }

    /// <summary>读取excel
    /// 默认第一行为标头
    /// </summary>
    /// <param name="path">excel文档路径</param>
    /// <returns></returns>
    public static DataTable RenderDataTableFromExcel(string path) {
        DataTable dt = new DataTable();

        HSSFWorkbook hssfworkbook;
        using (FileStream file = new FileStream(path, FileMode.Open, FileAccess.Read))
        {
            hssfworkbook = new HSSFWorkbook(file);
        }
        HSSFSheet sheet = hssfworkbook.GetSheetAt(0);
        System.Collections.IEnumerator rows = sheet.GetRowEnumerator();

        HSSFRow headerRow = sheet.GetRow(0);
        int cellCount = headerRow.LastCellNum;

        for (int j = 0; j < cellCount; j++)
        {
            HSSFCell cell = headerRow.GetCell(j);
            dt.Columns.Add(cell.ToString());
        }

        for (int i = (sheet.FirstRowNum + 1); i <= sheet.LastRowNum; i++)
        {
            HSSFRow row = sheet.GetRow(i);
            DataRow dataRow = dt.NewRow();

            for (int j = row.FirstCellNum; j < cellCount; j++)
            {
                if (row.GetCell(j) != null)
                    dataRow[j] = row.GetCell(j).ToString();
            }

            dt.Rows.Add(dataRow);
        }

        //while (rows.MoveNext())
        //{
        //    HSSFRow row = (HSSFRow)rows.Current;
        //    DataRow dr = dt.NewRow();

        //    for (int i = 0; i < row.LastCellNum; i++)
        //    {
        //        HSSFCell cell = row.GetCell(i);


        //        if (cell == null)
        //        {
        //            dr[i] = null;
        //        }
        //        else
        //        {
        //            dr[i] = cell.ToString();
        //        }
        //    }
        //    dt.Rows.Add(dr);
        //}

        return dt;
    }
}