using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;

namespace 用户登陆
{
    class Program
    {
        static void Main(string[] args)
        {
            string dataDir = AppDomain.CurrentDomain.BaseDirectory;
            if (dataDir.EndsWith(@"\bin\Debug\") || dataDir.EndsWith(@"\bin\Release\"))
            {
                dataDir = System.IO.Directory.GetParent(dataDir).Parent.Parent.FullName;
                AppDomain.CurrentDomain.SetData("DataDirectory", dataDir);
            }
            Console.WriteLine("请输入用户名：");
            string UserName = Console.ReadLine();
            Console.WriteLine("请输入密码:");
            string PassWord = Console.ReadLine();
            SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDBFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True");
            con.Open();
            //Console.WriteLine("打开数据库连接成功");
            SqlCommand cmd=con.CreateCommand();
            cmd.CommandText = "select * from T_users where username='"+UserName+"'";
            SqlDataReader reader = cmd.ExecuteReader();
            if (reader.Read())
            {
                //用户名存在
                string dbpassword = reader.GetString(reader.GetOrdinal("password"));
                if (PassWord == dbpassword)//我调试的时候看的是PassWord == dbpassword的，但是输出的时候输出的是密码错误，登陆失败，以前也是这样写的，这次就遇到这样的问题了。
                {
                    Console.WriteLine("登陆成功！");
                }
                else
                {
                    Console.WriteLine("密码错误，登陆失败！");
                }
            }
            else
            {
                Console.WriteLine("用户名不存在");
            }
            Console.ReadKey();
        }
      
    }
}