效果展示

程序关系

App,Config

DAL

using System;using System.Collections.Generic;using System.Data;using System.Linq;using System.Text;using System.Threading.Tasks;namespace FLogin.DAL{    /// 
    /// DAL-Student    /// 
    class Student    {        /// 
        /// 取得学员列表        /// 
        /// 
             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    {        /// 
        /// 对配置文件connnectionStrings节进行读取        /// 
        static string connstr = System.Configuration.ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;        /// 
        /// 查询数据库返回一张表        /// 
        ///         ///         /// 
             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;            }        }        /// 
        /// 对数据库进行增，删、该等活动        /// 
        ///         ///         /// 
             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();                }            }        }        /// 
        /// 对数据库进行查询        /// 
        ///         ///         /// 
             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    {        /// 
        /// 根据姓名取得用户,得到一行数据集        /// 
        ///         /// 
             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});        }        /// 
        /// 重置错误次数        /// 
        ///         /// 
             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});        }        /// 
        /// 更新错误时间        /// 
        ///         /// 
             public int UpDateLastErrTime(int _id)        {            return SqlHelper.ExecuteNonQuery("UPDATE dbo.UserInfo SET LastErrTime = GETDATE() WHERE id = @id",                new SqlParameter("@id", SqlDbType.Int) { Value = _id});        }        /// 
        /// 更新错误次数        /// 
        ///         /// 
             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    {        /// 
        /// 取的学员列表        /// 
        /// 
             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    {        /// 
        /// 判断是否登录成功！！        /// 
        ///         ///         /// 
             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    {        /// 
        /// 应用程序的主入口点。        /// 
        [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());            }                    }    }}