（超简单基础版）ASP.NET(.Net Framework)三层架构，结合sql server实现登录与注册

第一步：首先创建一个Models类库（解决方案上）

1.使用面向对象的方法封装一个UserInfo类

 public class UserInfo
    {
        public UserInfo()
        { }

        public UserInfo(int id, string uid, string pwd, string name, int age, string gender)
        {
            this.id = id;
            this.uid = uid;
            this.pwd = pwd;
            this.name = name;
            this.age = age;
            this.gender = gender;
        }
        public UserInfo( string uid, string pwd, string name, int age, string gender)
        {
            
            this.uid = uid;
            this.pwd = pwd;
            this.name = name;
            this.age = age;
            this.gender = gender;
        }

        public int id { get; set; }
        public string uid { get; set; }
        public string pwd { get; set; }
        public string name { get; set; }
        public int age{ get; set; }
        public string gender { get; set; }
    }

第二步：创建我们的 “打工仔” DAL 类库，将它与我们的Models层关联（展开选项，右击引用，添加引用）（解决方案上）

1.可爱的DBHelper登场（超超超简单版~）

 public class DBHelper
    {

        //连接对象
        public static SqlConnection con = new SqlConnection("server=.;database=DB2003;uid=sa;pwd=123");
        //判断连接是否打开
        public static void OpenOrClose()
        {
            if (con.State == ConnectionState.Open)
            {
                con.Close();
            }
            if (con.State == ConnectionState.Closed)
            {
                con.Open();
            }
        }
        //增删改
        public static bool Execute(string sql)
        {
            OpenOrClose();
            SqlCommand cmd = new SqlCommand(sql, con);
            int count = cmd.ExecuteNonQuery();//增删改方法
            OpenOrClose();
            return count > 0;
        }
        //非断开式查询
        public static SqlDataReader GetReader(string sql)
        {
            OpenOrClose();
            SqlCommand cmd = new SqlCommand(sql, con);
            return cmd.ExecuteReader(CommandBehavior.CloseConnection);
        }
        //断开式查询
        public static DataTable GetTable(string sql)
        {
            OpenOrClose();
            SqlDataAdapter sda = new SqlDataAdapter(sql, con);
            DataTable dt = new DataTable();
            sda.Fill(dt);
            OpenOrClose();
            return dt;
        }
    }

2.创建UserInfoDAL类

public  class UserInfoDAL
    {
        //使用非断开式查询
        public SqlDataReader GetReader(string uid, string pwd)
        {
            string sql = string.Format("SELECT * FROM user_info where uid='{0}' and pwd='{1}'", uid, pwd);
            return DBHelper.GetReader(sql);
        }
        //新增用户信息
        public bool AddUser(UserInfo user)
        {
            string sql = string.Format("insert into user_info values('{0}','{1}','{2}','{3}','{4}')"
                ,user.uid,user.pwd,user.name,user.age,user.gender);
            return DBHelper.Execute(sql);

        }
    }

第三步：创建我们的 “CEO”   BLL类库（解决方案上），将它与我们的Models、DAL层关联

1.同样，创建一个UserInfoBLL类

 public class UserInfoBLL
    {
        //调用UserInfoDAL的方法
        UserInfoDAL dal = new UserInfoDAL();

        public UserInfo Login(string uid, string pwd)
        {
         SqlDataReader reader=   dal.GetReader(uid ,pwd);
            UserInfo user = null;
            //判断SqlDataReader中是否有数据
            if (reader.Read())
            {
                user = new UserInfo();
                user.id = reader.GetInt32(0);
                user.uid = reader.GetString(1);
                user.pwd = reader.GetString(2);
                user.name = reader.GetString(3);
                user.age = reader.GetInt32(4);
                user.gender = reader.GetString(5);
            }
            DBHelper.OpenOrClose();
            return user;
        }
        //用户注册，
        public bool reg(string uid, string pwd, string name, int age, string gender)
        {
            return dal.AddUser(new UserInfo(uid, pwd, name, age, gender));
        }
    }

第四步：创建web窗体（项目上）将它与我们的Models、BLL层关联

1.1.创建登录页面

   

       

           

账号：
           

           

密码：
           

           

               
                注册
           

       

   

1.2.登录页面后台代码

public partial class Login : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            string uid = this.TextBox1.Text;
            string pwd = this.TextBox2.Text;

            UserInfoBLL bll = new UserInfoBLL();
            //调用BLL层的Login方法，返回用户对象
          UserInfo user=  bll.Login(uid,pwd);
            //根据用户对象是否为空，来判断登录操作是否成功
            if (user != null)
            {
                Session["user"] = user;
                Response.Redirect("Index.aspx");
            }
            else
            {
                Response.Write("");
            }
        }
    }

2.1.创建注册页面

   

       

           

用户注册

           

账号：
           

           

密码：
           

           

姓名：
           

           

年龄：
           

           

性别：
                男
                女
               
           

           

               
           

       

   

2.2.注册页面后台代码

 public partial class Reg : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            UserInfoBLL bll = new UserInfoBLL();
            if (bll.reg(txtuid.Text, txtpwd.Text, txtname.Text, int.Parse(txtage.Text), DropDownList1.Text))
            {
                Response.Write("");
            }
            else
            {
                Response.Write("");
            }
        }
    }

OK！大功告成！最后提示一下，如果要引用其他层的东西，记得alt + enter 一下，选择using 那个选项。