NPOI 教程---读写Excel

博客链接：

http://www.cnblogs.com/atao/category/209358.html

http://blog.csdn.net/zhumi/article/details/49076

http://tonyqus.sinaapp.com/tutorial

官网：http://npoi.codeplex.com/

NPOI官方网站：http://www.npoi.info/npoi2tutorial （教程系列）

示例：

using ExcelManager.Model;
using NPOI.HSSF.UserModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace ExcelManager.Helper
{
    public class ExportHelper
    {
        /// <summary>
        /// 导出入库表格
        /// </summary>
        /// <param name="List"></param>
        public static void ExportStorage(List<UserModel> List)
        {
            if (List.Count == 0)
            {
                return;
            }

            try
            {

                HSSFWorkbook hssfworkbook = new HSSFWorkbook();

                HSSFSheet sheet = (HSSFSheet)hssfworkbook.CreateSheet("Sheet1");
                sheet.SetColumnWidth(0, 256 * 15);//256*legth 设置列宽
                sheet.SetColumnWidth(1, 256 * 30);

                //创建列名
                HSSFRow rowHeader = (HSSFRow)sheet.CreateRow(0);
                rowHeader.CreateCell(0).SetCellValue("编号");
                rowHeader.CreateCell(1).SetCellValue("姓名");

                //创建表头
                HSSFRow rowContent = null;
                int rowIndex = 1;
                foreach (var item in List)
                {
                    rowContent = (HSSFRow)sheet.CreateRow(rowIndex++);
                    rowContent.CreateCell(0).SetCellValue(item.ID);
                    rowContent.CreateCell(1).SetCellValue(item.Name);
                }

                SaveExcel("测试", hssfworkbook);
            }
            catch (Exception ex)
            {
                LogUtil.Log("导出异常：" + ex.ToString());
                MessageBox.Show("导出失败");
            }
        }

        #region 保存文件
        /// <summary>
        /// 保存文件
        /// </summary>
        /// <param name="fileNamePrefix">文件名前缀</param>
        /// <param name="hssfworkbook">HSSFWorkbook</param>
        private static void SaveExcel(string fileNamePrefix, HSSFWorkbook hssfworkbook)
        {
            SaveFileDialog dialog = new SaveFileDialog();
            dialog.Filter = "Excel 工作表 (*.xls)|*.xls";
            dialog.RestoreDirectory = true;
            dialog.FileName = fileNamePrefix + "_" + DateTime.Now.ToString("yyyyMMdd_HHmmss");
            if (dialog.ShowDialog() == DialogResult.OK)
            {
                string path = dialog.FileName.ToString();
                using (FileStream file = new FileStream(path, FileMode.Create))
                {
                    hssfworkbook.Write(file);
                }
                MessageBox.Show("导出完成");
            }
        }
        #endregion
    }
}

将excel保存完后，如何下载文件到本地？

参考.Net MVC 怎么上传文件和下载文件