回顾状态模式：

根据不断的请求或者实时变化，更改状态
可对状态进行读取并更具判断，设置新的状态
不同的子状态重写抽象类状态，进行实时判断更改。

实战分析：

在上机中，要进行实时地余额判断，并进行余额不足和小于最低余额强制下机的操作
或许实时的余额变化，进行判断余额调整状态。
Sate类

public class StateModel
    {
        public abstract class State
        {
            public abstract string WriteProgram(Context context);
        }

        public class Context
        {
            //用到的实体
            private State current;
            private double consume;
            public double Consume { get => consume; set => consume = value; }
            public State Current { get => current; set => current = value; }


            public void SetState(State s)//改变初始状态，可读当前状态
            {
                Current = s;
            }
            public string WriteProgram()//请求的处理，并设置下一个状态
            {
                string a = Current.WriteProgram(this);
                return a;
            }


            public class StateOne : State//具体子状态1
            {
                public override string WriteProgram(Context context)
                {
                    string a = "null";
                    if (context.Consume >= 10)
                    {
                        a = "null";
                    }
                    else
                    {
                        context.SetState(new StateTwo());
                        context.WriteProgram();
                    }
                    return a;
                }
            }

            public class StateTwo : State//具体子状态2
            {
                public override string WriteProgram(Context context)
                {
                    string a = "null";
                    if (context.Consume < 10)
                    {
                        a = "余额不足10元，请尽快充值,以免影响上机！";
                    }
                    else
                    {
                        context.SetState(new StateThree()); context.WriteProgram();
                    }
                    return a;
                }
            }

            public class StateThree : State//具体子状态3
            {
                public override string WriteProgram(Context context)
                {
                    string a = "null";
                    if (context.Consume < 5)
                    {
                        a = "余额不足5元，正在下机";
                    }
                    return a;
                }

            }


        }

外观层进行传值

//连接状态模式
        public string InquireyStat(LineInfo outline)
        {
            StateModel.Context cs = new StateModel.Context();
            cs.Consume = outline.Cash;
            string a = cs.WriteProgram();
            Entity.Gloable.Time++;
            return a;
        }

UI层判断

 private void txtOnUserID_EnabledChanged(object sender, EventArgs e)
        {
            if (txtOnUserID.Enabled == false)//当确定用户已上机，则启动状态模式，实时判断余额情况
            {
                timerOut.Enabled = true;//计时器开始运行
                timerOut.Start();//启动计时器          
            }
        }

        private void timerOut_Tick(object sender, EventArgs e)
        {
            //student 表 select
            Entity.StudentInfo student = new Entity.StudentInfo();
            student.UserID = Convert.ToInt32(txtOutUserID.Text.Trim());
            DataTable table1;
            Facade.OutLineFacade facade = new Facade.OutLineFacade();
            table1 = facade.SelectStudentFacade(student);

            //line_info表，插入上下机记录表 insert
            Entity.LineInfo outline = new Entity.LineInfo();

            int balance = Convert.ToInt32(table1.Rows[0][2].ToString());//学生表余额

            outline.Consume_time = Convert.ToString(Gloable.Time);//??

            //每一小时查看余额
            string a = facade.InquireyStat(outline);
            if (a == "null")
            {
                return;
            }
            else
            {
                MessageBox.Show(a, "提示");
                if (a == "余额不足5元，下机")
                {
                    //调用下事件
                    btnOutLogin_Click(sender, e);
                    timerOut.Start();
                }
            }
        }

还有不完善的地方，多指正