说明:数据的导入导出功能在企业中还是比较常用的,下面先介绍txt文件的导入导出,但是企业中一般是用Excel导入导出

1 先建UI页面　　

2清空数据库数据

 

3 导入数据

4导出数据

代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Configuration;using System.Data;using System.Data.SqlClient;using System.Drawing;using System.IO;using System.Linq;using System.Text;using System.Text.RegularExpressions;using System.Threading.Tasks;using System.Windows.Forms;using Microsoft.Win32.SafeHandles;namespace UserLogin{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        //导入        private void btnImport_Click(object sender, EventArgs e)        {            //1、找到文件--这里使用OpenfileDialog类            using (OpenFileDialog ofd = new OpenFileDialog())            {                //1-01设置标题                ofd.Title = "请选择要导入的文件";                //1-02设置初识路径                ofd.InitialDirectory = @"C:\Users\home\Desktop";                //1-03 设置文件类型                ofd.Filter = "文本文件|*.txt";                if (ofd.ShowDialog() == DialogResult.OK)                {                    this.txtSelectFile.Text = ofd.FileName;                    //导入数据                    ImportData(ofd.FileName);                    MessageBox.Show("导入成功");                }            }        }        //导出        private void btnExport_Click(object sender, EventArgs e)        {            //1、找到文件--这里使用OpenfileDialog类            using (OpenFileDialog ofd = new OpenFileDialog())            {                //1-01设置标题                ofd.Title = "请选择要导出的文件路径";                //1-02设置初识路径                ofd.InitialDirectory = @"C:\Users\home\Desktop";                //1-03 设置文件类型                ofd.Filter = "文本文件|*.txt";                if (ofd.ShowDialog() == DialogResult.OK)                {                    this.txtExport.Text = ofd.FileName;                    //导入数据                    ExportData();                    MessageBox.Show("导出成功");                }            }                  }        private void ImportData(string fileName)        {            string temp = string.Empty;            //2、读取文件            using (StreamReader reader = new StreamReader(fileName,Encoding.UTF8))            {                reader.ReadLine();//去掉第一行                                //32-01连接数据库字符串                string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;                //3-02创建连接对象                SqlConnection conn = new SqlConnection(connStr);                using (conn)                {                    //3-03创建数据库执行对象                    SqlCommand cmd = new SqlCommand();                    cmd.Connection = conn;                    conn.Open();                    using (cmd)                    {                        //如果下一行数据不为空,继续执行                        while (!string.IsNullOrEmpty(temp = reader.ReadLine()))                        {                            string[] strs = temp.Split(new string[]{
    "\t"}, StringSplitOptions.RemoveEmptyEntries);                            //创建sql语句                            cmd.CommandText = string.Format("insert into UserInfo ( Pwd, StuName, StuAge, Delflag, ClassNo) values ({0},'{1}',{2},{3},{4})", strs[1], strs[2], strs[3], strs[4], strs[5]);                            cmd.ExecuteNonQuery();                        }                    }                }            }                    }        private void ExportData()        {            //连接数据库字符串            //32-01连接数据库字符串            string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;            //3-02创建连接对象            SqlConnection conn = new SqlConnection(connStr);            using (conn)            {                conn.Open();                using (System.Data.SqlClient.SqlCommand command = conn.CreateCommand())                {                    command.CommandText = "select * from UserInfo";                    using (System.Data.SqlClient.SqlDataAdapter adp = new System.Data.SqlClient.SqlDataAdapter(command))                    {                        System.Data.DataTable dt = new System.Data.DataTable();                        adp.Fill(dt);                        DataRow[] myRow = dt.Select();                        int cl = dt.Columns.Count;                        if (cl <= 0)                        {                            MessageBox.Show("数据不存在");                        }                        using (FileStream fsWrite= new FileStream(txtExport.Text.Trim(),FileMode.OpenOrCreate,FileAccess.Write))                        {                            #region 写数据                            //逐行写入数据                            foreach (DataRow row in myRow)                            {                                string ls_item = string.Empty;                                for (int i = 0; i < cl; i++)                                {                                    if (i == (cl - 1))                                    {                                        ls_item += row[i].ToString() + "\r\n";                                    }                                    else                                    {                                        ls_item += row[i].ToString() + "\t";                                    }                                                                   }                                byte[] buffer = Encoding.UTF8.GetBytes(ls_item);                                fsWrite.Write(buffer, 0, buffer.Length);                            }                            #endregion                             }                                           }                }                          }        }           }}