Net学习日记_三层_1_登录页面总结篇_残缺版

效果展示

程序关系

App,Config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <connectionStrings>
    <add name="connStr" connectionString="server=PC201609230944\SQL2005;database=HeiMaBlog;user=sa;pwd=123456"/>
  </connectionStrings>
</configuration>

DAL

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

namespace FLogin.DAL
{
    /// <summary>
    /// DAL-Student
    /// </summary>
    class Student
    {
        /// <summary>
        /// 取得学员列表
        /// </summary>
        /// <returns></returns>
        public DataTable GetStudents()
        {
            return SqlHelper.ExecuteDataTable("SELECT * FROM dbo.Student");
        }

    }
}

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

namespace FLogin.DAL
{
    class SqlHelper
    {
        /// <summary>
        /// 对配置文件connnectionStrings节进行读取
        /// </summary>
        static string connstr = System.Configuration.ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;

        /// <summary>
        /// 查询数据库返回一张表
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static DataTable ExecuteDataTable(string sql, params SqlParameter[] parameters)
        {
            // 创建临时数据集，内存。
            DataSet ds = new DataSet();
            // 创建适配器对象
            SqlDataAdapter adapter = new SqlDataAdapter(sql, connstr);
            // 给适配器对象的查询命令对象添加参数
            adapter.SelectCommand.Parameters.AddRange(parameters);
            try
            {
                // 充填数据集
                adapter.Fill(ds);
                return ds.Tables[0];
            }
            catch
            {
                return null;
            }
        }

        /// <summary>
        /// 对数据库进行增，删、该等活动
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static int ExecuteNonQuery(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection conn = new SqlConnection(connstr))
            {
                using (SqlCommand cmd = new SqlCommand(sql, conn))
                {
                    cmd.Parameters.AddRange(parameters);
                    conn.Open();
                    return cmd.ExecuteNonQuery();
                }
            }
        }

        /// <summary>
        /// 对数据库进行查询
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static object ExecuteScalar(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection conn = new SqlConnection(connstr))
            {
                using (SqlCommand cmd = new SqlCommand(sql, conn))
                {
                    cmd.Parameters.AddRange(parameters);
                    conn.Open();
                    return cmd.ExecuteScalar();
                }
            }
        }

    }
}

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

namespace FLogin.DAL
{
    class UserInfo
    {
        /// <summary>
        /// 根据姓名取得用户,得到一行数据集
        /// </summary>
        /// <param name="_name"></param>
        /// <returns></returns>
        public DataTable GetUserByName(string _name)
        {
            return SqlHelper.ExecuteDataTable("SELECT * ,DATEDIFF(MINUTE,LastErrTime,GETDATE())FROM dbo.UserInfo WHERE UserName =@UserName",
                new SqlParameter("@UserName", SqlDbType.NVarChar) { Value = _name});
        }

        /// <summary>
        /// 重置错误次数
        /// </summary>
        /// <param name="_id"></param>
        /// <returns></returns>
        public int ReSetErrTimes(int _id)
        {
            SqlParameter sp = new SqlParameter();
            sp.ParameterName = "@id";
            sp.Value = _id;
            return SqlHelper.ExecuteNonQuery("UPDATE dbo.UserInfo SET ErrTimes=0 WHERE id = @id",
                new SqlParameter("@id", SqlDbType.Int) { Value = _id});
        }

        /// <summary>
        /// 更新错误时间
        /// </summary>
        /// <param name="_id"></param>
        /// <returns></returns>
        public int UpDateLastErrTime(int _id)
        {
            return SqlHelper.ExecuteNonQuery("UPDATE dbo.UserInfo SET LastErrTime = GETDATE() WHERE id = @id",
                new SqlParameter("@id", SqlDbType.Int) { Value = _id});
        }

        /// <summary>
        /// 更新错误次数
        /// </summary>
        /// <param name="_id"></param>
        /// <returns></returns>
        public int UpDateErrTimes(int _id)
        {
            return SqlHelper.ExecuteNonQuery("update UserInfo Set ErrTimes=ErrTimes+1 where id=@id",
                new SqlParameter("@id", SqlDbType.Int) { Value=_id});
        }

    }
}

BLL

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

namespace FLogin.BLL
{
    class Student
    {
        /// <summary>
        /// 取的学员列表
        /// </summary>
        /// <returns></returns>
        public DataTable GetStudents()
        {
            DAL.Student dal = new DAL.Student();
            return dal.GetStudents();
        }
    }
}

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

namespace FLogin.BLL
{
    class UserInfo
    {

        /// <summary>
        /// 判断是否登录成功！！
        /// </summary>
        /// <param name="_name"></param>
        /// <param name="_pwd"></param>
        /// <returns></returns>
        public bool ChechLogin(string _name, string _pwd)
        {
            DAL.UserInfo dal = new DAL.UserInfo();
            DataTable dt = dal.GetUserByName(_name);

            // 三种情况：1.账号不存在 2.密码错误 3.登录锁定

            // 这个判断只能存在一个账户。
            if (dt.Rows.Count != 1) { return false; }

            DataRow dr = dt.Rows[0];
            if (Convert.ToInt32(dr[5]) < 15)
            {
                return false;
            }
            if (dr[2].ToString() == _pwd)
            {
                dal.ReSetErrTimes(Convert.ToInt32(dr[0]));// 登录成功后，重置错误次数
                return true;
            }
            else
            {
                // 密码不正确
                // 更新错误次数，更新数据库，dr里面的数据是在更新之前就取出来了。
                dal.UpDateErrTimes(Convert.ToInt32(dr[0]));
                // 错误三次就更新错误时间
                if (Convert.ToInt32(dr[3]) + 1 == 3)
                {
                    dal.UpDateLastErrTime(Convert.ToInt32(dr[0]));//记录最后错误时间
                    dal.ReSetErrTimes(Convert.ToInt32(dr[0]));//重置错误次数
                }
                return false;
            }
 
        }

    }
}

Flogin

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 FLogin
{
    public partial class FLogin : Form
    {
        public FLogin()
        {
            InitializeComponent();
        }

        private void btnOK_Click(object sender, EventArgs e)
        {
            // 设置当前窗口对系那个DialogResult就会关闭窗口，并且有返回值
            // 前提是这个窗口是被ShowDialog出现的
            // ShowDialog的返回值就是这设置的DialogResult
            BLL.UserInfo bll = new BLL.UserInfo();
            if (bll.ChechLogin(tbName.Text, tbPassWord.Text))
            {
                this.DialogResult = DialogResult.OK;
            }
            else
            {
                MessageBox.Show("登录失败！！");
            }
        }

        private void btnSorry_Click(object sender, EventArgs e)
        {
            this.DialogResult = DialogResult.Cancel;
        }


    }
}

FMain

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 FLogin
{
    public partial class FMain : Form
    {
        public FMain()
        {
            InitializeComponent();
        }

        private void 学员管理ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FStu fs = new FStu();
            //设置将一个窗口显示在这个窗口内部，前提，这个窗口是一个多文档窗口(isMdiContainer=true)
            fs.MdiParent = this;
            fs.Show();
        }
    }
}

FStu

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 FLogin
{
    public partial class FStu : Form
    {
        public FStu()
        {
            InitializeComponent();
        }

        private void FStu_Load(object sender, EventArgs e)
        {
            BLL.Student bll = new BLL.Student();
            DataTable table = bll.GetStudents();
            dvgMain.DataSource = table;
        }
    }
}

Program

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace FLogin
{
    static class Program
    {
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            // 首先创建窗体对象
            FLogin f1 = new FLogin();
            if (f1.ShowDialog() == DialogResult.OK)
            {
                Application.Run(new FMain());
            }


            
        }
    }
}