NPOI

读写Excel文件：

using NPOI.SS.UserModel;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using NPOI.XSSF.UserModel;
using NPOI.HSSF.UserModel;
namespace ExcelNPOI01
{
    class Program
    {
        static void Main(string[] args)
        {
            #region 读取文件


            //通过流的方式获取文件
            using (FileStream fsRead = new FileStream("123.xlsx", FileMode.Open, FileAccess.Read))
            {
                //创建工作表
                IWorkbook workBook = WorkbookFactory.Create(fsRead);
                //获取页
                ISheet sheet = workBook.GetSheetAt(0);
                //获取行--最后一行
                for (int i = 0; i <= sheet.LastRowNum; i++)
                {
                    IRow row = sheet.GetRow(i);
                    //遍历所有的单元格
                    StringBuilder sb = new StringBuilder();
                    for (int j = 0; j < row.LastCellNum; j++)
                    {
                        //获取单元格
                        ICell cell = row.GetCell(j);
                        //判断单元格的数据类型
                        if (cell.CellType == CellType.Numeric)
                        {
                            sb.Append(cell.NumericCellValue);//单元格的数据
                        }
                        if (cell.CellType == CellType.String)
                        {
                            sb.Append(cell.StringCellValue);
                        }
                    }
                    Console.WriteLine(sb.ToString());
                }
                Console.ReadKey();
            } 
            #endregion

            //写入文件
            List<Person> list = new List<Person>();
            list.Add(new Person() { Name = "卡卡西", Age = 1, Gender = "男" });
            list.Add(new Person() { Name = "地主", Age = 2, Gender = "男" });
            list.Add(new Person() { Name = "独角兽", Age = 40, Gender = "女" });
            list.Add(new Person() { Name = "凤姐", Age = 4, Gender = "女" });
            //流
            using (FileStream fsWrite = new FileStream("person.xlsx", FileMode.Create, FileAccess.Write))
            {
                //创建工作表
                XSSFWorkbook work = new XSSFWorkbook();//2007
                //HSSFWorkbook work = new HSSFWorkbook();//2003 改一下 person.xls
                //创建页
                ISheet sheet = work.CreateSheet("人");
                //创建行
                for (int i = 0; i < list.Count; i++)
                {
                    IRow row = sheet.CreateRow(i);
                    ICell cell = row.CreateCell(0, CellType.String);
                    cell.SetCellValue(list[i].Name);//姓名

                    ICell cell1 = row.CreateCell(1, CellType.Numeric);
                    cell1.SetCellValue(list[i].Age);//年龄

                    ICell cell2 = row.CreateCell(2, CellType.String);
                    cell2.SetCellValue(list[i].Gender);//性别
                }
                work.Write(fsWrite);
            }
            Console.WriteLine("OK");
        }
    }
    class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
        public string Gender { get; set; }

    }


}