C#将查询到的数据库里面的数据输出到textbox控件

C#连接数据库（类的形式）

using System;
using System.Collections.Generic;
using System.ComponentModel;
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 systemprotect
{
    public partial class bdwxx : Form
    {
        public bdwxx()
        {
            InitializeComponent();
        }

        private void bdwxx_Load(object sender, EventArgs e)
        {//C#将查询到的数据库里面的数据输出到textbox控件
            this.Text = "本单位信息--系统维护";
            DataCon link = new DataCon();//类的内容见博客上面的链接
            string sql = "select * from message";
            //为指定的command对象执行DataReader
            SqlDataReader read = link.query(sql);//执行sql语句
            while (read.Read())
            {
                Console.WriteLine("{0} {1} ", read["b_id"],read["b_name"]);
                textBox1.Text = read["b_id"].ToString();//b_id字段名，下同
                textBox2.Text = read["b_name"].ToString();
                textBox3.Text = read["b_tel"].ToString();
                textBox4.Text = read["b_person"].ToString();
                textBox5.Text = read["b_adress"].ToString();
            }
            link.close();
            Console.ReadLine();
            textBox1.ReadOnly = true;
            textBox2.ReadOnly = true;
            textBox3.ReadOnly = true;
            textBox4.ReadOnly = true;
            textBox5.ReadOnly = true;
        }

        private void s(object sender, EventArgs e)
        {

        }

        private void toolStripButton4_Click(object sender, EventArgs e)
        {
            Formmainxtwh1 form = new Formmainxtwh1();
            form.Show();
            this.Hide();
        }

        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            textBox1.ReadOnly = false;
            textBox2.ReadOnly = false;
            textBox3.ReadOnly = false;
            textBox4.ReadOnly = false;
            textBox5.ReadOnly = false;
        }

        private void toolStripButton2_Click(object sender, EventArgs e)
        {
            string id = textBox1.Text;
            string name = textBox2.Text;
            string tel = textBox3.Text;
            string person = textBox4.Text;
            string address = textBox5.Text;
            DataCon link = new DataCon();
            string update = "Update message set b_id='" + id + "',b_name='"+name+ "',b_tel='"+tel+ "',b_person='" + person + "',b_adress='" + address + "'";
            link.insert(update);
            link.close();
        }

        private void textBox3_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == 0x20) e.KeyChar = (char)0;  //禁止空格键
            if ((e.KeyChar == 0x2D) && (((TextBox)sender).Text.Length == 0)) return;   //处理负数
            if (e.KeyChar > 0x20)
            {
                try
                {
                    double.Parse(((TextBox)sender).Text + e.KeyChar.ToString());
                }
                catch
                {
                    e.KeyChar = (char)0;   //处理非法字符
                }
            }

        }

        private void toolStripButton3_Click(object sender, EventArgs e)
        {
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
            textBox5.Text = "";
        }

        private void toolStripButton5_Click(object sender, EventArgs e)
        {
            Formmainxtwh1 form = new Formmainxtwh1();
            form.Show();
            this.Hide();
        }
    }
}