NPOI 导出Excel

找到dll文件引用

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

namespace NPOI.WriteExcel
{
    class Program
    {
        /*NPOI.DLL：NPOI 核心函式庫。
        NPOI.DDF.DLL：NPOI 繪圖區讀寫函式庫。
        NPOI.HPSF.DLL：NPOI 文件摘要資訊讀寫函式庫。
        NPOI.HSSF.DLL：NPOI Excel BIFF 檔案讀寫函式庫。
        NPOI.Util.DLL：NPOI 工具函式庫。
        NPOI.POIFS.DLL：NPOI OLE 格式存取函式庫。
        ICSharpCode.SharpZipLib.DLL：檔案壓縮函式庫。
         */
        static void Main(string[] args)
        {
            new Program().CreateExcel();
            new Program().InsertContext();
        }

        /// <summary>
        /// 创建Excel
        /// </summary>
        private void CreateExcel()
        {

            HSSFWorkbook workbook = new HSSFWorkbook();
            FileStream filestream = new FileStream(AppDomain.CurrentDomain.BaseDirectory+DateTime.Now.ToString("yyyyMMddHHmmss")+".xls",FileMode.Create);

            // 新增試算表。 
            workbook.CreateSheet("試算表 A");
            workbook.CreateSheet("試算表 B");
            workbook.CreateSheet("試算表 C");

            workbook.Write(filestream);
            workbook.Close();
            
            filestream.Close();
            filestream.Dispose();
        }

        /// <summary>
        /// 像Excel中添加内容
        /// </summary>
        private void InsertContext()
        {
            HSSFWorkbook workbook = new HSSFWorkbook();
            FileStream filestream = new FileStream(AppDomain.CurrentDomain.BaseDirectory + DateTime.Now.ToString("yyyyMMddHHmmss") + ".xls", FileMode.Create);

            // 新增試算表。 
            ISheet sheet1 = workbook.CreateSheet("試算表 A");
            ISheet sheet2 = workbook.CreateSheet("試算表 B");
            ISheet sheet3 = workbook.CreateSheet("試算表 C");

            //依次创建行和列
            for (int i = 0; i < 10; i++)
            {
                IRow row1 = sheet1.CreateRow(i);
                IRow row2 = sheet2.CreateRow(i);
                IRow row3 = sheet3.CreateRow(i);

                for (int j = 0; j < 10; j++)
                {
                    ICell cell1 = row1.CreateCell(j);
                    cell1.SetCellValue("第" + (i + 1) + "行，第" + (j + 1) + "列");
                    ICell cell2 = row2.CreateCell(j);
                    cell2.SetCellValue("第" + (i + 1) + "行，第" + (j + 1) + "列");
                    ICell cell3 = row3.CreateCell(j);
                    cell3.SetCellValue("第" + (i + 1) + "行，第" + (j + 1) + "列");
                }
            }

            workbook.Write(filestream);
            workbook.Close();

            filestream.Close();
            filestream.Dispose();
        }
    }
}

应用中。。。。。

  HSSFWorkbook workbook = new HSSFWorkbook();
            FileStream filestream = new FileStream(AppDomain.CurrentDomain.BaseDirectory + DateTime.Now.ToString("yyyyMMddHHmmss") + ".xls", FileMode.Create);

            // 新增試算表。 
            ISheet sheet1 = workbook.CreateSheet("試算表 A");
            ISheet sheet2 = workbook.CreateSheet("試算表 B");
            ISheet sheet3 = workbook.CreateSheet("試算表 C");



            //创建表头  
            IRow rowHead = sheet1.CreateRow(0);
            rowHead.CreateCell(0).SetCellValue("序号");
            sheet1.SetColumnWidth(0, 256 * 15);

            rowHead.CreateCell(1).SetCellValue("QQ");
            sheet1.SetColumnWidth(1, 256 * 25);

            rowHead.CreateCell(2).SetCellValue("名称");
            sheet1.SetColumnWidth(2, 256 * 20);

            rowHead.CreateCell(3).SetCellValue("时间");
            sheet1.SetColumnWidth(3, 256 * 15);
             
            //依次填充值

            string beginTime = this.dateTimePicker1.Value.ToString().Split(' ')[0];
            string endTime = this.dateTimePicker2.Value.ToString();
            pagesize = Convert.ToInt32(this.label4.Text);
            DataSet ds = bll.GetList("", beginTime, endTime, Inum, pagesize, out allCount);

            for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
            {
                //创建第二行，并赋值
                IRow rowHead2 = sheet1.CreateRow(i+1);
                rowHead2.CreateCell(0).SetCellValue(ds.Tables[0].Rows[i][0].ToString());
                rowHead2.CreateCell(1).SetCellValue(ds.Tables[0].Rows[i][1].ToString());
                rowHead2.CreateCell(2).SetCellValue(ds.Tables[0].Rows[i][2].ToString());
                rowHead2.CreateCell(3).SetCellValue(ds.Tables[0].Rows[i][3].ToString());
            }
 

            workbook.Write(filestream);
            workbook.Close();

            filestream.Close();
            filestream.Dispose();