C# winform如何对excel文件进行导入导出——NPOI文件

1.创建winform窗体，添加导入导出按钮，添加gridControl（需要下载dev插件）没有的话添加DatagridView也可以。如下图所示：

 2.开始写代码，首先在项目的引用文件下添加NPOI文件（需要下载，之前在哪下载的忘记了，可以百度瞅瞅）。

3.然后引用其命名空间

 4.限制其可读取的excel类型，先添加一个命名空间IO。 

5.在导入按钮中书写代码

  DataTable Table()
        {
            DataTable d = new DataTable();
            d.Columns.Add("name");
            d.Columns.Add("sex");
            d.Columns.Add("phone");
            d.Columns.Add("address");
            return d;

        }

        //导入按钮
        private void btnImport_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            //清空表头
            gridView1.Columns.Clear();

            //清空数据集
            gridControl1.DataSource = null;

            string _msg = "";
            try
            {
                if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
                {
                    string _filePath = openFileDialog1.FileName;
                    if (_filePath != "")
                    {
                        using (FileStream fs = new FileStream(_filePath, FileMode.Open, FileAccess.Read))
                        {
                            IWorkbook wk = GetWorkBook(fs, _filePath);
                            DataTable dt = Table();
                            ISheet hsheet = wk.GetSheetAt(0);

                            int _lastRow = hsheet.LastRowNum;
                            IRow _row = hsheet.GetRow(1);
                            for (int i = 1; i <= _lastRow; i++)
                            {
                                _row = hsheet.GetRow(i);
                                if (_row.GetCell(0) == null)
                                {
                                    break;
                                }
                                _row.GetCell(0).SetCellType(CellType.String);
                                string name = _row.GetCell(0).StringCellValue; //姓名
                                if (name == "") ;
                                {
                                    break;
                                }
                                _row.GetCell(1).SetCellType(CellType.String);
                                string sex = _row.GetCell(1).StringCellValue;//性别

                                _row.GetCell(2).SetCellType(CellType.String);
                                string phone = _row.GetCell(2).StringCellValue; //电话号

                                _row.GetCell(3).SetCellType(CellType.String);
                                string address = _row.GetCell(3).StringCellValue;//家庭住址

                                DataRow dr = dt.NewRow();
                                dr["name"] = name;
                                dr["sex"] = sex;
                                dr["phone"] = phone;
                                dr["address"] = address;
                                dt.Rows.Add(dr);
                            }
                            gridControl1.DataSource = dt;
                            gridView1.BestFitColumns();
                        }
                        _msg = "共导入" + (gridView1.RowCount).ToString() + "笔记录！";
                    }
                }
            }
            catch (Exception es)
            {
                _msg = es.Message;
            }
            finally
            {
                if (_msg != "")
                {
                    MessageBox.Show(_msg, "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
            }

        }

6.现在我们需要写一个类来封装导出excel的方法，新建一个ExportToExcel类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using DevExpress.XtraPivotGrid;
using DevExpress.XtraGrid;
using DevExpress.XtraPrinting;
using System.Windows.Forms;

namespace 窗体导入导出文件
{
    class ExportToExcel
    {
        public static void GridToXlsx(GridControl gctr, string filename)
        {
            SaveFileDialog saveFile = new SaveFileDialog();
            saveFile.Filter = "Excel文件(.xlsx)|*.xlsx";
            saveFile.FileName = filename;
            if (saveFile.ShowDialog() == DialogResult.OK)
            {
                gctr.ExportToXlsx(saveFile.FileName);
                MessageBox.Show("成功导出Excel文件！");
            }
        }
        public static void GridToXls(GridControl gctr, string filename)
        {
            SaveFileDialog saveFile = new SaveFileDialog();
            saveFile.Filter = "Excel文件(*.xls)|*.xls";
            saveFile.FileName = filename;
            if (saveFile.ShowDialog() == DialogResult.OK)
            {
                gctr.ExportToXlsx(saveFile.FileName);
                MessageBox.Show("成功导出Excel文件！");
            }
        }
        public static void GridToExcel(GridControl gctr, string filename)
        {
            SaveFileDialog saveFile = new SaveFileDialog();
            saveFile.Filter = "Excel2003(*.xls)|*.xls|Excel2007(*.xlsx)|*.xlsx";
            saveFile.FileName = filename;
            if (saveFile.ShowDialog() == DialogResult.OK)
            {
                if (saveFile.FilterIndex == 1)
                {
                    gctr.ExportToXlsx(saveFile.FileName);
                }
                else if (saveFile.FilterIndex == 2)
                {
                    gctr.ExportToXlsx(saveFile.FileName);
                    MessageBox.Show("成功导出Excel文件！");
                }
            }
        }

    }
}

7.导入按钮书写代码

    //导出按钮
    private void btnExport_ItemClick(objectsenderDevExpress.XtraBars.ItemClickEventArgs e)
        {
            ExportToExcel.GridToExcel(gridControl1, "学生信息表");
        }