C#WinFrom导出Excel

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using NPOI.SS.UserModel;        //NPOI
using NPOI.HSSF.Util;           //NPOI
using NPOI.HSSF.UserModel;      //NPOI
using NPOI.XSSF.UserModel;      //NPOI
using System.IO;
namespace ESMT
{
    public class ExportExcel
    {
        /// 

        /// 
        /// 
        /// 数据表
        /// 工作簿名字
        /// 文件路径
        /// 列头
        public void ExportToExcel(DataGridView grdview, string sheetName, string FilePath, string[] columnTitle)
        {

            //不允许dataGridView显示添加行，负责导出时会报最后一行未实例化错误
            grdview.AllowUserToAddRows = false;
            HSSFWorkbook workbook = new HSSFWorkbook();
            ISheet sheet = workbook.CreateSheet(sheetName);//创建工作簿
            //设置表头
            IRow headerRow = sheet.CreateRow(0);//创建第一行
            headerRow.HeightInPoints = 40;
            headerRow.CreateCell(0).SetCellValue("出库表单");//单元格赋值
            ICellStyle headStyle = workbook.CreateCellStyle();
            headStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;//格式居中
            IFont font = workbook.CreateFont();
            font.Boldweight = 500;
            font.FontHeightInPoints = 20;
            headStyle.SetFont(font);
            headerRow.GetCell(0).CellStyle = headStyle;
            sheet.AddMergedRegion(new NPOI.SS.Util.CellRangeAddress(0, 0, 0, grdview.ColumnCount - 2));//单元格合并 最后个参数是合并个数

            IRow headerRow2 = sheet.CreateRow(1);//创建第二行列头
            ICellStyle headStyle2 = workbook.CreateCellStyle();
            headStyle2.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
            IFont font2 = workbook.CreateFont();
            font2.FontHeightInPoints = 10;
            font2.Boldweight = 700;
            headStyle2.SetFont(font2);
            for (int l = 0; l 1; l++) //列头填值
            {
                headerRow2.CreateCell(l).SetCellValue(columnTitle[l]);
                headerRow2.GetCell(l).CellStyle = headStyle2;
            }

            //设置列宽
            for (int l = 0; l )
            {
                sheet.DefaultColumnWidth = 15;
            }

            //填写内容
            for (int i = 0; i )
            {
                IRow row = sheet.CreateRow(i + 2);
                for (int j = 1; j )
                {
                    row.CreateCell(j - 1, CellType.String).SetCellValue(grdview.Rows[i].Cells[j].Value.ToString());//j-1表示哪个单元格
                }
            }

            using (FileStream stream = File.OpenWrite(FilePath))//创建Excel并写入数据
            {
                workbook.Write(stream);
                stream.Close();
            }
            GC.Collect();
        }
    }
}

 string[] columnTitle = { "序号", "仓位", "Facility", "供应商料号", "料号", "料卷ID", "料卷数量", "储位号", "Date Code/Lot", "生产日期", "供应商编码", "入仓时间" };
            string localFilePath = "";// fileNameExt, newFileName, FilePath; 
            SaveFileDialog sfd = new SaveFileDialog();//保存文件窗口
            //设置文件类型 
            sfd.Filter = "Excel(97-2003)|*.xls";//保存类型为EXCEL
            //保存对话框是否记忆上次打开的目录 
            sfd.RestoreDirectory = true;

            //点了保存按钮进入 
            if (sfd.ShowDialog() == DialogResult.OK)
            {
                localFilePath = sfd.FileName.ToString(); //获得文件路径 
                ex.ExportToExcel(grdData, "出库表单", localFilePath, columnTitle);
            }