c# NPOI 导出EXCEL

需要引入dll文件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CSR_Web.Common
{
    public   class NPOIExport
    {
        public static NPOI.HSSF.UserModel.HSSFWorkbook DoExport(System.Data.DataTable dt, string notile)
        {

            //创建工作簿
            NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();
            //创建表
            NPOI.SS.UserModel.ISheet sheet = book.CreateSheet(notile);
            //自适应列宽
          //  sheet.AutoSizeColumn(1, true);
            //标题行合并单元格
            sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, dt.Columns.Count-1));

            NPOI.SS.UserModel.IRow firstrow = sheet.CreateRow(0);
            NPOI.SS.UserModel.ICell firstcell = firstrow.CreateCell(0);

            //表名样式
            NPOI.SS.UserModel.ICellStyle styleHeader = book.CreateCellStyle();
            NPOI.SS.UserModel.IFont fontHeader = book.CreateFont();
            styleHeader.Alignment =NPOI.SS.UserModel.HorizontalAlignment.Center;
            styleHeader.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center;
            fontHeader.FontHeightInPoints =20;

            styleHeader.SetFont(fontHeader);
            firstcell.CellStyle = styleHeader;
            firstcell.SetCellValue(notile);

            try
            {
                //列名样式
                NPOI.SS.UserModel.ICellStyle styleColName = book.CreateCellStyle();
                NPOI.SS.UserModel.IFont fontColName = book.CreateFont();
                styleColName.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
                styleColName.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center;
                fontColName.FontHeightInPoints = 14;
                styleColName.SetFont(fontColName);

                //数据的样式、字体大小
                NPOI.SS.UserModel.ICellStyle styleBody = book.CreateCellStyle();
                NPOI.SS.UserModel.IFont fontBody = book.CreateFont();

                styleBody.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
                styleBody.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center;
                fontBody.FontHeightInPoints = 12;
                styleBody.SetFont(fontBody);

                //创建具体单元格数据
                int rowCount = dt.Rows.Count;
                int colCount = dt.Columns.Count;

                NPOI.SS.UserModel.IRow colNameRow = sheet.CreateRow(1);
                for (int x = 0; x < colCount; x++) { //将列名写入单元格
                    NPOI.SS.UserModel.ICell colNameCell = colNameRow.CreateCell(x);
                    colNameCell.SetCellValue(dt.Columns[x].ColumnName);
                    colNameCell.CellStyle = styleColName;
                }

                    for (int i = 0; i < rowCount; i++)
                    {
                        NPOI.SS.UserModel.IRow row = sheet.CreateRow(i + 2);//数据从第三上开始 第一行表名 第二行列名

                        for (int j = 0; j < colCount; j++)
                        {
                            //填充数据
                            NPOI.SS.UserModel.ICell cell = row.CreateCell(j);

                            if (dt.Rows[i][j] != null)
                            {

                                cell.SetCellValue(dt.Rows[i][j].ToString());
                            }
                            else
                            {
                                cell.SetCellValue("");
                            }

                            cell.CellStyle = styleBody;
                        }
                    }
                //自适应列宽
                for (int x = 0; x < colCount; x++)
                {
                    sheet.AutoSizeColumn(x, true);
                }

                //此处代码是将 xls文件发到页面通过浏览器直接下载到本地　　可以放到　界面调用的地方
                //System.IO.MemoryStream ms = new System.IO.MemoryStream();
                //book.Write(ms);
                //Response.AddHeader("Content-Disposition", string.Format("attachment; filename=绩效统计.xls"));
                //Response.BinaryWrite(ms.ToArray());
                //book = null;
                //ms.Close();
                //ms.Dispose();  

                return book;
            }
            catch {
            throw new Exception();
            }finally{
                book=null;
            }

        }

    }
}

  /// <summary>
        ///导出
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btnExport_Click(object sender, EventArgs e)
      {

            DataTable dt = cmbll.getdt();

            NPOI.HSSF.UserModel.HSSFWorkbook book = NPOIExport.DoExport(dt, "xxx报表");
            //写入客户端
            try
            {
                WriteClient(book);
            }
            catch
            {

            }
            finally
            {

                book = null;
            }

        }

        public void WriteClient(NPOI.HSSF.UserModel.HSSFWorkbook book)
        {
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            book.Write(ms);
            Response.AddHeader("Content-Disposition", string.Format("attachment; filename=客户资料"+DateTime.Now.ToString("yyyyMMddHHmmss")+".xls"));
            Response.BinaryWrite(ms.ToArray());
            book = null;
            ms.Close();
            ms.Dispose();
        }