NewLibrary/Book_manger/Sql/Form1.cs

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;
using System.Security.Cryptography;

namespace Sql
{
    public partial class Form1 : Form//进行接口拆分，Form1被拆分了，还有一部分在放在Form1.Designer.cs里 :Form就是继承自Form
    {        //
        public Form1()
        {
            InitializeComponent();//该方法实际上是由系统生成的对于窗体界面的定义方法，会跳转到Form1.Designer.cs，这个是对界面进行初始化
            //在每一个Form文件建立后，都会同时产生程序代码文件.CS文件，以及与之相匹配的.Designer.CS文件，
            //业务逻辑以及事件方法等被编写在.CS文件之中，而界面设计规则被封装在.Designer.CS文件里


        }//做完这个初始化操作以后就弹出登录框了，等待下一步的命令执行
        public string MD5Hash(string input)//对数据进行md5加密
        {
            MD5 md5 = MD5.Create();
            byte[] inputBytes = Encoding.ASCII.GetBytes(input);
            byte[] hashBytes = md5.ComputeHash(inputBytes);

            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < hashBytes.Length; i++)
            {
                sb.Append(hashBytes[i].ToString("X2"));
            }
            return sb.ToString();
        }
        private void timer1_Tick(object sender, EventArgs e)
        {
            if(pictureBox1.Location.X<175)//图片校准功能，就是不确定我们的图片大小是怎么样的，但是为了实现滑动功能，将图片从左到右滑动，于是来一个图片校准
            {
                pictureBox1.Location = new Point(pictureBox1.Location.X + 4, pictureBox1.Location.Y);
            }
            else
            {
                if(comboBox1.Text=="学生")
                {
                    string A = MD5Hash(textBox2.Text);
                    string sql = "select * from Student where Id='" + textBox1.Text + "'and Password='" + A + "'";
                    Dao dao = new Dao();
                    IDataReader dr = dao.read(sql);
                    dr.Read();
                    string sID = dr["Id"].ToString();
                    Form3 form3 = new Form3(sID);
                    form3.Show();
                    this.Hide();
                   // this.Close();
                }
                else 
                {
                    if (comboBox1.Text == "老师")
                    {
                        Form2 form2 = new Form2();
                        form2.Show();
                        this.Hide();
                        // this.Close();
                    }
                    else 
                {
                    if (comboBox1.Text == "管理员")//滑动完了以后就进行判断，管理员的话就走这一条
                    {
                        Form5 form5 = new Form5();//创建一个form5窗体
                        form5.Show();//form5窗体展示，跳转到form5.Designer.cs文件进行窗体初始化
                        this.Hide();//form1窗体隐藏
                        // this.Close();                       
                    }
                }
                }                
                timer1.Stop();//timer1定时器停止，然后打开了form5等待使用者进行操作
            }
        }

        private void button1_Click(object sender, EventArgs e)//点击登录以后触发了这个事件
        {
            if(login())//这个是一个登录判断，然后进入到login()里面去进行判断，在下面89行
            {
                timer1.Start();//启动定时器，待会准备运行timer1_Tick()
                textBox1.Visible = false;
                textBox2.Visible = false;
                label1.Visible = false;
                label2.Visible = false;
                label3.Visible = false;
                comboBox1.Visible = false;
                button1.Visible = false;
                button3.Visible = false;
                button4.Visible = false;
                button6.Visible = false;
            }
            else if(textBox1.Text != "" && textBox2.Text != "" && comboBox1.Text != "")
            {
                MessageBox.Show("账号或密码有误", "警告", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
        }
        private bool login()
        {
            if (textBox1.Text == "" || textBox2.Text == ""||comboBox1.Text=="")//逻辑与，两个都为真才行，也就是判断这三个框都不能为空
            {
                MessageBox.Show("输入不完整", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);//提示是行头，里面的文字是输入不完整
                return false;
            }
            if (comboBox1.Text == "学生")//如果框框是学生那么走下面的判断，下面的管理员也一样
            {
                string A = MD5Hash(textBox2.Text);
                string sql = "select * from Student where Id='" + textBox1.Text + "'and Password='"+A+"'";
                Dao dao = new Dao();
                IDataReader dr = dao.read(sql);
                if(dr.Read())
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            if (comboBox1.Text == "老师")
            {
                string A = MD5Hash(textBox2.Text);
                string sql = "select * from seat where Name='" + textBox1.Text + "'and Password='" + A + "'";
                Dao dao = new Dao();
                IDataReader dr = dao.read(sql);
                if (dr.Read())
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            if (comboBox1.Text == "管理员")
            {
                string A = MD5Hash(textBox2.Text);
                string sql = "select * from Admin where Id='" + textBox1.Text + "'and Password='" + A + "'";//sql语句进行拼接
                Dao dao = new Dao();//创建一个Dao对象，准备通过Dao对数据库进行操作
                IDataReader dr = dao.read(sql);//dao层的read函数载入sql语句开始查询，然后将结果给到dr
                if (dr.Read())//如果数据库的读取成功，那么返回成功，离开到139行
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            return false;
        }
        private void button3_Click(object sender, EventArgs e)
        {
            if (textBox1.Text != "" || textBox2.Text != "" || comboBox1.Text != "")
            {
                DialogResult r = MessageBox.Show("退出后当前输入内容不会保存", "提示", MessageBoxButtons.OKCancel);
                if (r == DialogResult.OK)
                {
                    Close();
                }
            }
            else
            {
                Close();
            }
        }

        private void button4_Click(object sender, EventArgs e)
        {
            textBox1.Text = null;
            
        }
        private void button6_Click(object sender, EventArgs e)
        {
            textBox2.Text = null;
        }

        private void pictureBox1_Click(object sender, EventArgs e)
        {

        }
    }
}