1、登录功能

登陆成功界面

登陆成功界面

关键代码

// 点击“登录”按钮则登录系统
        private void bt_Login_Click(object sender, EventArgs e)
        {
            String connStr = ConfigurationManager.ConnectionStrings["Attendance"].ConnectionString;
            SqlConnection sqlConn = new SqlConnection(connStr);
            try
            {
                // 连接数据库
                sqlConn.Open();

                // 构造命令发送给数据库
                String sqlStr = "select * from EMPLOYEE where ID=@id and PASSWORD=@pwd";
                SqlCommand cmd = new SqlCommand(sqlStr, sqlConn);

                // 注意是用用户ID登录，而不是用户名，用户名可能会重复
                cmd.Parameters.Add(new SqlParameter("@id", this.tb_User.Text.Trim()));
                cmd.Parameters.Add(new SqlParameter("@pwd", this.tb_Password.Text.Trim()));

                SqlDataReader dr = cmd.ExecuteReader();

                // 如果从数据库中查询到记录，则表示可以登录
                if (dr.HasRows)
                {
                    dr.Read();
                    UserInfo.userId = int.Parse(dr["id"].ToString());
                    UserInfo.userName = dr["name"].ToString();
                    UserInfo.userPwd = dr["password"].ToString();
                    UserInfo.userQx = dr["role"].ToString();
                    UserInfo.userAge = dr["gender"].ToString();

                    MessageBox.Show(UserInfo.userQx + "登录成功");
                    if (UserInfo.userQx == "管理员")
                    {
                        // 显示库管员主界面
                        MainFormAdmin formAdmin = new MainFormAdmin();
                        formAdmin.Show();

                        // 隐藏登录界面
                        this.Hide();
                    }
                    if (UserInfo.userQx == "职员")
                    {
                        // 显示收银员主界面
                        MainFormUser formUser = new MainFormUser();
                        formUser.Show();

                        // 隐藏登录界面
                        this.Hide();
                    }


                }
                else
                {
                    MessageBox.Show("用户名或密码错误", "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
            catch (Exception exp)
            {
                MessageBox.Show("访问数据库错误：" + exp.Message);
            }
            finally
            {
                sqlConn.Close();
            }
        }

2、注册功能

注册界面

注册界面

编号自动生成代码

 private void NewUserForm_Load(object sender, EventArgs e)
        {
            String connStr = ConfigurationManager.ConnectionStrings["Attendance"].ConnectionString;
            SqlConnection sqlConn = new SqlConnection(connStr);
            try
            {
                // 连接数据库
                sqlConn.Open();
               
                String sqlStr = "select MAX(id+1) as id from EMPLOYEE";
                SqlCommand cmd = new SqlCommand(sqlStr, sqlConn);
                SqlDataReader dr = cmd.ExecuteReader();
                dr.Read();
                this.id.Text = dr[0].ToString();

                // 如果从数据库中查询到记录，则表示可以登录

            }

关键代码

private void zc_Click(object sender, EventArgs e)
        {
             // 点击“确认”按钮，则录入信息
     
            String id = this.id.Text.Trim();
            String name = this.name.Text.Trim();
            String pwd = this.pwd.Text.Trim();
            String age = this.age.Text.Trim();
            String sex = this.sex.Text.Trim();
            String bm = this.bm.Text.Trim();
            String qx = this.qx.Text.Trim();
            /*int supplier = int.Parse(this.cbb_Supplier.SelectedValue.ToString());*/
            

            // 更新数据库
            String connStr = ConfigurationManager.ConnectionStrings["Attendance"].ConnectionString;
            SqlConnection sqlConn = new SqlConnection(connStr);
            try
            {
                // 连接数据库
                sqlConn.Open();

                // 构造命令
                String sqlStr = "insert into EMPLOYEE(ID, NAME, PASSWORD, AGE, QX, SEX, BM) values(@id, @name, @pwd, @age, @qx, @sex, @bm )";
                SqlCommand cmd = new SqlCommand(sqlStr, sqlConn);

                // SQL字符串参数赋值
                cmd.Parameters.Add(new SqlParameter("@id", id));
                cmd.Parameters.Add(new SqlParameter("@name", name));
                cmd.Parameters.Add(new SqlParameter("@pwd", pwd));
                cmd.Parameters.Add(new SqlParameter("@age", age));
                cmd.Parameters.Add(new SqlParameter("@qx", qx));
                cmd.Parameters.Add(new SqlParameter("@sex", sex));
                cmd.Parameters.Add(new SqlParameter("@bm", bm));
                
                // 将命令发送给数据库
                int res = cmd.ExecuteNonQuery();

                // 根据返回值判断是否插入成功
                if (res != 0)
                {
                    MessageBox.Show("员工信息录入成功");
                }
                else
                {
                    MessageBox.Show("员工信息录入失败");
                }
            }
            catch (Exception exp)
            {
                MessageBox.Show("访问数据库错误：" + exp.Message);
            }
            finally
            {
                sqlConn.Close();
            }
        }