NPOI操作

C#操作Excel，如果格式是xlsx的就用openXML来操作，如果是xls的就用NPOI来操作

应该讲第三方组件，单独存在一个lib文件夹中，然后添加引用，这样组件就能随着项目走

xlsx实际上是一个压缩文件

using System;
using System.Windows.Forms;
using System.IO;
using NPOI.HSSF.UserModel;

namespace NPOI测试
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 读取EXCEL
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            using (FileStream stream = new FileStream(@"F:\username.xls", FileMode.Open, FileAccess.Read))
            {
                HSSFWorkbook workbook = new HSSFWorkbook(stream);
                MessageBox.Show(workbook.GetSheetName(0),"获取的Sheet名");  //获取sheet名
                HSSFSheet sheet= workbook.GetSheetAt(0); //获得第一页的sheet表
                HSSFRow row=sheet.GetRow(0);  //获得第一行
                HSSFCell cell=row.GetCell(0);  //获得第一列
                string s=cell.ToString();   //输出显示[0][0]单元的内容
                MessageBox.Show(s,"获取Excel中[0][0]单元的内容");
                //MessageBox.Show(cell.StringCellValue);//输出显示字符串单元格的内容

                 MessageBox.Show(sheet.LastRowNum.ToString(),"Excel中最后一行的行号");//获取最后总共有多少行

                 MessageBox.Show(row.LastCellNum.ToString(), "Excel中最后一列的行号");//获取当前行总共有多少列
            }
        }

        /// <summary>
        /// 写入Excel
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            HSSFWorkbook workbook = new HSSFWorkbook();
            HSSFSheet sheet = workbook.CreateSheet();
            HSSFRow row = sheet.CreateRow(0);//创建第一行
            row.CreateCell(0, HSSFCell.CELL_TYPE_STRING).SetCellValue("Hello");//在第一行第一格写上“Hello”
            row.CreateCell(1, HSSFCell.CELL_TYPE_NUMERIC).SetCellValue(3.14);//写上浮点型的数字
            using (FileStream stream = new FileStream(@"f:\1.xls", FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
                workbook.Write(stream);
            }
            MessageBox.Show("创建成功");
           }   

      }
}