using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace DataView
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            //01-创建配置文件  添加引用
            //02-设置连接字符串]
            string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
            //03 创建连接字符串
            using (SqlConnection conn = new SqlConnection(connStr))
            {
                //04-创建数据库操作脚本
                string sqlStr = "select EmpId, Pwd, StuName, StuAge, Delflag, ClassNo from UserInfo";
                using (SqlDataAdapter sda = new SqlDataAdapter(sqlStr,conn))
                {
                    //05-隆重介绍一下Adapter-适配器
                    //05-01判断sqlConnection是否初始化
                    //05-02初始化Select Command对象
                    //05-03 通过cmd对象执行返回SQLdataReader对象
                    //05-04 读取数据,填充到datatreader上
                    DataTable dt =  new DataTable();
                    sda.Fill(dt);
                    //05-创建实体模型,对数据进行封装
                    List<UserINfo> userList = new List<UserINfo>();
                    foreach (DataRow dataRow in dt.Rows)
                    {
                        //封装数据
                        userList.Add(new UserINfo() { EmpId = int.Parse(dataRow["EmpId"].ToString()),
                                                      StuName = dataRow["StuName"].ToString(),
                                                      StuAge = int.Parse(dataRow["StuAge"].ToString())
                                                    });
                      
                        
                    }
                    //06-设置数据源
                    this.dataGridView1.DataSource = userList;

                }
            }
           



        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace DataView
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            //01-创建配置文件  添加引用
            //02-设置连接字符串]
            string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
            //03 创建连接字符串
            using (SqlConnection conn = new SqlConnection(connStr))
            {
                //04-创建数据库操作脚本
                string sqlStr = @"
                select ClassId, ClassName from ClassInfo;
                select EmpId, Pwd, StuName, StuAge, Delflag, ClassNo from UserInfo";
                using (SqlDataAdapter sda = new SqlDataAdapter(sqlStr,conn))
                {
                    //05-隆重介绍一下Adapter-适配器
                    //05-01判断sqlConnection是否初始化
                    //05-02初始化Select Command对象
                    //05-03 通过cmd对象执行返回SQLdataReader对象
                    //05-04 读取数据,填充到datatreader上
                  
                    DataSet ds = new DataSet();
                    sda.Fill(ds);
                    List<UserINfo> userList = new List<UserINfo>();
                    foreach (DataRow dataRow in ds.Tables[1].Rows)
                    {
                        //封装数据
                        userList.Add(new UserINfo()
                        {
                            EmpId = int.Parse(dataRow["EmpId"].ToString()),
                            StuName = dataRow["StuName"].ToString(),
                            StuAge = int.Parse(dataRow["StuAge"].ToString())
                        });


                    }
                    this.dataGridView1.DataSource = userList;
                }
            }
           



        }
    }
}