(深入.Net平台的软件系统分层开发).第一章.上机练习.20170424

==========================================实体层==========================================

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MySchool.Models
{
    /// <summary>
    /// 年级信息
    /// </summary>
    public class GradeInfo
    {
        /// <summary>
        /// 年级ID
        /// </summary>
        public int GradeId { get; set; }
        /// <summary>
        /// 年级名称
        /// </summary>
        public string GradeName { get; set; }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MySchool.Models
{
    /// <summary>
    /// 登录信息
    /// </summary>
    public class LoginInfo
    {
        /// <summary>
        /// 登录Id
        /// </summary>
        public string LoginId { get; set; }
        /// <summary>
        /// 登录密码
        /// </summary>
        public string LoginPwd { get; set; }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MySchool.Models
{
    /// <summary>
    /// 学生信息实体
    /// </summary>
    public class StudentInfo
    {
        /// <summary>
        /// 学生姓名
        /// </summary>
        public string StudentName { get; set; }
        /// <summary>
        /// 学生学号
        /// </summary>
        public string StudentNo { get; set; }
        /// <summary>
        /// 性别
        /// </summary>
        public string Sex { get; set; }
        /// <summary>
        /// 年级
        /// </summary>
        public string GradeName { get; set; }
        /// <summary>
        /// 电话
        /// </summary>
        public string Phone { get; set; }
        /// <summary>
        /// 密码
        /// </summary>
        public string PWD { get; set; }
    }
}

==========================================访问数据层==========================================

using MySchool.Models;
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MySchool.DAL
{
    /// <summary>
    /// 访问数据层
    /// </summary>
    public class MySchoolDAL
    {
        /// <summary>
        /// 获取登录账号、密码
        /// </summary>
        /// <returns>List<LoginInfo></returns>
        public List<LoginInfo> GetLoginInfo()
        {
            DBHelper db = new DBHelper();
            string sql = "select * from Admin ";
            //登录信息泛型集合
            List<LoginInfo> loginInfo = new List<LoginInfo>();

            db.connection.Open();
            SqlCommand cmd = new SqlCommand(sql,db.connection);
            SqlDataReader reader = cmd.ExecuteReader();
            //循环读取sql语句读取出来的数据
            while (reader.Read())
            {
                //将登录Id 密码 赋给对应属性
                LoginInfo li = new LoginInfo();
                li.LoginId = reader["LoginId"].ToString();
                li.LoginPwd = reader["LoginPwd"].ToString();
                //添加到登录信息泛型集合
                loginInfo.Add(li);
            }

            //关闭
            reader.Close();
            db.connection.Close();
            //返回登录信息泛型集合
            return loginInfo;
        }

        /// <summary>
        /// 获取登录账号、密码
        /// </summary>
        /// <returns>List<LoginInfo></returns>
        public List<LoginInfo> LoginInfo()
        {
            DBHelper db = new DBHelper();
            string sql = "select * from Admin ";
            //登录信息泛型集合
            List<LoginInfo> loginInfo = new List<LoginInfo>();
            DataSet ds = db.Adapter(sql);
            foreach (DataRow item in ds.Tables[0].Rows)
            {
                LoginInfo li = new LoginInfo();
                li.LoginId = item["LoginId"].ToString();
                li.LoginPwd = item["LoginPwd"].ToString();
                loginInfo.Add(li);
            }
            return loginInfo;
        }


        /// <summary>
        /// 获取数据库年级信息
        /// </summary>
        /// <returns></returns>
        public List<GradeInfo> GetGradeInfo()
        {
            string sql = "select * from grade ";
            List<GradeInfo> gradeInfo = new List<GradeInfo>();
            DBHelper db = new DBHelper();
            DataSet ds = db.Adapter(sql);
            foreach (DataRow dr in ds.Tables[0].Rows)
            {
                GradeInfo gi = new GradeInfo();
                gi.GradeId = (int)(dr["GradeId"]);
                gi.GradeName = dr["GradeName"].ToString();
                gradeInfo.Add(gi);
            }
            return gradeInfo;
        }

        /// <summary>
        /// 获取学生信息
        /// </summary>
        public List<StudentInfo> GetStudentInfo()
        {
            List<StudentInfo> studentInfo = new List<StudentInfo>();
            string sql = "select * from Student inner join Grade on Grade.GradeId = Student.GradeId ";
            DBHelper db = new DBHelper();
            DataSet ds = db.Adapter(sql);
            foreach (DataRow dr in ds.Tables[0].Rows)
            {
                StudentInfo si = new StudentInfo();
                si.GradeName = dr["GradeName"].ToString();
                si.Phone = dr["Phone"].ToString();
                si.PWD = dr["LoginPwd"].ToString();
                if (dr["Gender"].ToString().Equals("True"))
                {
                    si.Sex = "男";
                }
                else
                {
                    si.Sex = "女";
                }
                si.StudentName = dr["StudentName"].ToString();
                si.StudentNo = dr["StudentNo"].ToString();
                studentInfo.Add(si);
            }
            return studentInfo;
        }
    }
}

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

namespace MySchool.DAL
{
   public class DBHelper
    {
        static string con = "server=.;database=MySchool;user=sa;pwd=123";
        public SqlConnection connection = new SqlConnection(con);

        public DataSet Adapter(string sql)
        {
            DataSet ds = new DataSet();
            SqlDataAdapter sda = new SqlDataAdapter(sql, connection);
            sda.Fill(ds);
            return ds;
        }
    }
}

==========================================业务逻辑层==========================================

using MySchool.DAL;
using MySchool.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MySchool.BLL
{
    /// <summary>
    /// 业务逻辑层
    /// </summary>
    public class MySchoolBLL
    {
        /// <summary>
        /// 账号密码是否正确
        /// </summary>
        /// <param name="userName">用户名</param>
        /// <param name="pwd">密码</param>
        /// <returns>是否正确</returns>
        public bool isR(string userName,string pwd)
        {
            MySchoolDAL dal = new MySchoolDAL();
            //获取登录信息泛型集合
            List<LoginInfo> loginInfo = dal.LoginInfo();
            //遍历登录信息泛型集合  判断输入的账号密码是否存在
            foreach (var item in loginInfo)
            {
                if (item.LoginId.Equals(userName) && item.LoginPwd.Equals(pwd))
                {
                    return true;
                }
            }
            return false;
        }

        /// <summary>
        /// 获取学生信息
        /// </summary>
        /// <returns></returns>
        public List<StudentInfo> GetList()
        {
            MySchoolDAL mySchoolDal = new MySchoolDAL();
            List<StudentInfo> studentInfo = new List<StudentInfo>();
            studentInfo = mySchoolDal.GetStudentInfo();

            return studentInfo;
        }

        /// <summary>
        /// 按照年级获取新学生列表
        /// </summary>
        /// <param name="gradeId"></param>
        /// <returns></returns>
        public List<StudentInfo> GetNewList(string gradeName)
        {
            List<StudentInfo> studentInfo = GetList();

            List<StudentInfo> newStudentInfo = new List<StudentInfo>();
            for (int i = 0; i < studentInfo.Count; i++)
            {
                if (studentInfo[i].GradeName.Equals(gradeName))
                {
                    newStudentInfo.Add(studentInfo[i]);
                }
            }
            return newStudentInfo;
        }


        /// <summary>
        /// 获取年级信息
        /// </summary>
        /// <returns></returns>
        public List<GradeInfo> GetGrade()
        {
            List<GradeInfo> gradeInfo = new List<GradeInfo>();
            MySchoolDAL md = new MySchoolDAL();
            gradeInfo = md.GetGradeInfo();
            return gradeInfo;
        }
    }
}

==========================================用户界面层==========================================

----------------------------------------登录界面----------------------------------------

using MySchool.BLL;
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;

namespace SJ3
{
    public partial class frmLogin : Form
    {
        public frmLogin()
        {
            InitializeComponent();
        }

        //单击登录
        private void btnLogin_Click(object sender, EventArgs e)
        {
            MySchoolBLL mb = new MySchoolBLL();
            //调用账号密码是否正确方法
            bool isR = mb.isR(txtUserName.Text,txtPWD.Text);
            if (isR == true)
            {
                MessageBox.Show("登录成功");
                frmList fl = new frmList();
                fl.ShowDialog();
            }
            else
            {
                MessageBox.Show("登录失败，账号或者密码错误");
            }
        }

        //单击退出
        private void btnCancel_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

----------------------------------------学生列表界面----------------------------------------

using MySchool.BLL;
using MySchool.Models;
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;

namespace SJ3
{
    public partial class frmList : Form
    {
        public frmList()
        {
            InitializeComponent();
        }

        //加载
        private void frmList_Load(object sender, EventArgs e)
        {
            BangCmb();
        }

        /// <summary>
        /// 绑定年级组合框
        /// </summary>
        public void BangCmb()
        {
            MySchoolBLL mb = new MySchoolBLL();
            List<GradeInfo> gradeInfo = mb.GetGrade();
            cmbGrade.DataSource = gradeInfo;
            cmbGrade.DisplayMember = "GradeName";
            cmbGrade.ValueMember = "GradeId";
        }

        /// <summary>
        /// 按照年级绑定学生列表
        /// </summary>
        public void BangList()
        {
            MySchoolBLL mb = new MySchoolBLL();
            List<StudentInfo> studentInfo = mb.GetNewList(cmbGrade.Text);
            dataGridView1.DataSource = studentInfo;
        }

        //更改组合框内容
        private void cmbGrade_SelectedIndexChanged(object sender, EventArgs e)
        {
            BangList();
        }
    }
}