C#登陆密码代码

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

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string sqlstring = "Data Source=zhs31;Initial Catalog=database;Integrated Security=True;Connect Timeout=15;Encrypt=False;TrustServerCertificate=False;";
            SqlConnection a = new SqlConnection(sqlstring); a.Open();
            SqlCommand b = new SqlCommand("select * from [登陆]", a);
            SqlDataReader c = b.ExecuteReader(); while (c.Read())
            {
                if (this.textBox1.Text.Equals(c["user"].ToString()) && this.textBox2.Text.Equals(c["password"].ToString()))
                { MessageBox.Show("cuowu"); }
               // else