ExportService.cs 2.11 KB
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Text;

namespace HHECS.Application.Service
{
    /// <summary>
    /// 导出成excel服务类
    /// 1、web数据表格转为dt
    /// 2、确认文件名以及保存文件的地址
    /// 3、dt数据表保存到excel
    /// </summary>
    public class ExportService
    {
        /// <summary>
        /// 数据表转Excel
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="file"></param>
        public static void TableToExcel(DataTable dt, string file)
        {
            IWorkbook workbook;
            string fileExt = Path.GetExtension(file).ToLower();
            if (fileExt == ".xlsx") { workbook = new XSSFWorkbook(); } else if (fileExt == ".xls") { workbook = new HSSFWorkbook(); } else { workbook = null; }
            if (workbook == null) { return; }
            ISheet sheet = string.IsNullOrEmpty(dt.TableName) ? workbook.CreateSheet("Sheet1") : workbook.CreateSheet(dt.TableName);

            //表头
            IRow row = sheet.CreateRow(0);
            for (int i = 0; i < dt.Columns.Count; i++)
            {
                ICell cell = row.CreateCell(i);
                cell.SetCellValue(dt.Columns[i].ColumnName);
            }

            //数据
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                IRow row1 = sheet.CreateRow(i + 1);
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    ICell cell = row1.CreateCell(j);
                    cell.SetCellValue(dt.Rows[i][j].ToString());
                }
            }

            //转为字节数组
            MemoryStream stream = new MemoryStream();
            workbook.Write(stream);
            var buf = stream.ToArray();

            //保存为Excel文件
            using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))
            {
                fs.Write(buf, 0, buf.Length);
                fs.Flush();
            }
        }
    }
}