导出Excel文件，npoi方式和通过microsoft.visual basic.dll

一：例子截图：

二：NPOI截图

三：EmployeeListWindow.cs代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using HRMSys.DAL;
using HRMSys.Model;
using System.Data.SqlClient;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using System.IO;

namespace HYMSys.UI.EmployeeMgr
{
    public partial class EmployeeListWindow : Form
    {
        public EmployeeListWindow()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 加载所有信息
        /// </summary>
        public EmployeeList[] load()
        {
            EmployeeDAL de = new EmployeeDAL();
            
           return de.ListAll();
           

            
        }
       
        /// <summary>
        /// 添加员工
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void toolsb_add_Click(object sender, EventArgs e)
        {
            EmployeeEditWindow edit = new EmployeeEditWindow();
            edit.IsAdd = true;
            edit.ShowDialog();

            if (edit.IsLoad == true)
            {
                dataGridView1.DataSource = load();
            }

        }
        /// <summary>
        /// 删除员工
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void toolsb_delete_Click(object sender, EventArgs e)
        {
            Guid id=(Guid)dataGridView1.CurrentRow.Cells[0].Value;
            string name=(string)dataGridView1.CurrentRow.Cells[2].Value;//这里的cell是相对于list员工操作窗口上name这列,即使第二行
            if (MessageBox.Show("真的要删除---"+name+"---吗?","警告!",MessageBoxButtons.OKCancel)==DialogResult.OK)
            {
                EmployeeDAL dal = new EmployeeDAL();
                dal.DeleteById(id);
                dataGridView1.DataSource = load();
            }
            
        }
        /// <summary>
        /// 修改员工信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void toolsb_edit_Click(object sender, EventArgs e)
        {
            EmployeeEditWindow edit = new EmployeeEditWindow();
           edit.EditId = (Guid)dataGridView1.CurrentRow.Cells[0].Value;
           edit.IsAdd = false;
            edit.ShowDialog();
            if (edit.IsLoad == true)
            {
                dataGridView1.DataSource = load();
            }

        }
        /// <summary>
        /// 自动加载所有员工信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void EmployeeListWindow_Load(object sender, EventArgs e)
        {
            DepartmentDAL dal = new DepartmentDAL();
            cb_depart.DataSource = dal.ListAll();
            cb_depart.DisplayMember = "Name";
            cb_depart.ValueMember = "Id";
            //cb_depart.SelectedValue=

            dtp_indate.Value = DateTime.Today.AddMonths(-1);
            dtp_enddate.Value = DateTime.Today;

            
            dataGridView1.DataSource= load();


            
        }
        /// <summary>
        /// 综合查询
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            List<string> wherelist = new List<string>();
            List<SqlParameter> parameter = new List<SqlParameter>();
            if (ckb_name.Checked == true) 
            {
                wherelist.Add("Name=@Name");
                parameter.Add(new SqlParameter("@Name",tb_name.Text));
 
            }
            if (ckb_indate.Checked == true)
            {
                wherelist.Add("InDate>=@InDateStart and InDate<=@InDateEnd");
                parameter.Add(new SqlParameter("@InDateStart",dtp_indate.Value));
                parameter.Add(new SqlParameter("@InDateEnd",dtp_enddate.Value));
            }
            if (ckb_depart.Checked == true)
            {
                wherelist.Add("DepartmentId=@DepartmentId");
                parameter.Add(new SqlParameter("@DepartmentId",cb_depart.SelectedValue));
            }



            string whereSql=string.Join(" and ",wherelist);
            string Sql="select * from T_Employee";
            if (whereSql.Length > 0)
            {
                Sql = Sql + " where " + whereSql;
            }
            EmployeeDAL dal = new EmployeeDAL();
            dataGridView1.DataSource= dal.SearchBySome(Sql, parameter);
           



        }
        /// <summary>
        /// 导出到Excel
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void tsb_outputExcel_Click(object sender, EventArgs e)
        {
            SaveFileDialog saFi = new SaveFileDialog();//打开保存对话框
            saFi.Filter = "Excel文件|*.xls";//设置文件类型
            if (saFi.ShowDialog() != DialogResult.OK)//如果未打开对话框,返回
            {
                return;
            }
            string path = saFi.FileName;//得到文件的路径
            HSSFWorkbook workbook = new HSSFWorkbook();//创建一个Excel文档
            ISheet sheet = workbook.CreateSheet("员工操作");//创建一个Excel的页

            IRow rowheader = sheet.CreateRow(0);//创建一个行,作为行头号
            rowheader.CreateCell(0, CellType.STRING).SetCellValue("姓名");//第一行第一列显示姓名
            rowheader.CreateCell(1, CellType.STRING).SetCellValue("工号");
            rowheader.CreateCell(2, CellType.STRING).SetCellValue("入职日期");

            EmployeeList[] list = (EmployeeList[])dataGridView1.DataSource;//得到datagridview的数据源,Excel的写入文件
            for (int i = 0; i < list.Length; i++)//将写入的数据与Excel的单元格对应
            {
                EmployeeList li = list[i];//得到数据组的单条信息
                IRow row = sheet.CreateRow(i + 1);//创建一行
                row.CreateCell(0, CellType.STRING).SetCellValue(li.Name);//将这行的第一列填上姓名
                row.CreateCell(1, CellType.STRING).SetCellValue(li.Number);

                //存入date这种格式的转换
                ICellStyle datestyle = workbook.CreateCellStyle();//创建一个单元格样式
                IDataFormat dateformamt = workbook.CreateDataFormat();//创建一个数据的固定格式

                datestyle.DataFormat = dateformamt.GetFormat("yyyy"年"m"月"d"日"");//日期的样式采用这种数据格式
                //存日期的单元格指定他的格式
                ICell indate = row.CreateCell(2, CellType.NUMERIC);
                indate.CellStyle = datestyle;

                indate.SetCellValue(li.InDate);//给存日期的单元指定数据
 
            }
            //Excel写入数据流
            using(Stream stream=File.OpenWrite(path))//创建一个写入流
            {
                workbook.Write(stream);//Excel写入数据流
            }

        }
    }
}

四：通过microsoft.visual basic.dll来导出

a.添加引用

b.调出excel,由于这个方法每次运行都会开一个进程，太占资源，没上面方法好用，这里不再做过多的介绍

c.