状态模式

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace fd
{
public class Account
{
public AccountState State { set; get; }
public string Owner { set; get; }
public double Balance { set; get; }

public Account(string owner, double initialAmount)
{
Owner = owner;
Balance = initialAmount;
State = new VistorState(this);
}

public void SetBalance(double amount)
{
Balance = amount;

}

public void Deposit(double amount)
{
Console.WriteLine("存入" + amount);
State.Deposit(amount);

}

public void Shopping(double amount)
{
Console.WriteLine("消费" + amount);
State.Shopping(amount);

}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace fd
{

public abstract class AccountState
{
protected Account _account;

public abstract void Deposit(double amount);
public abstract void Shopping(double amount);
public abstract void StateCheck();
}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace fd
{

class Program
{
static void Main(string[] args)
{
Account account = new Account("白石麻衣", 666666);
Console.WriteLine("开户成功。姓名==>" + account.Owner + " 初始金额==>" + account.Balance );

account.Deposit(56);
Console.WriteLine("===================================");

}
}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace fd
{

public class VistorState:AccountState
{
public VistorState(Account account)
{
_account = account;
StateCheck();
}

public override void Deposit(double amount)
{
_account.Balance += amount;
Console.WriteLine( amount + "元，存款后的账户余额为：" + _account.Balance);
StateCheck();
}

public override void Shopping(double amount)
{
double newBalance = _account.Balance - amount;
if (newBalance > 0)
{
_account.Balance -= amount;
Console.WriteLine( amount + "元，账户余额：" + _account.Balance);
}

StateCheck();
}

public override void StateCheck()
{
if (_account.Balance > 100 && _account.Balance < 1000)
{
_account.State = new MemberState(_account);
}
else if (_account.Balance > 1000)
{
_account.State = new VIPState(_account);
}
}
}

public class VIPState : AccountState
{
public VIPState(Account account)
{
_account = account;
}

public override void Deposit(double amount)
{
_account.Balance += amount;
Console.WriteLine(amount + "元，存款后的账户余额为：" + _account.Balance);
StateCheck();
}

public override void Shopping(double amount)
{
double newBalance = _account.Balance - amount;
if (newBalance > 0)
{
_account.Balance -= amount;
Console.WriteLine(amount + "元，账户余额：" + _account.Balance);
}
StateCheck();
}

public override void StateCheck()
{
if (_account.Balance > 0 && _account.Balance < 100)
{
_account.State = new VistorState(_account);
}
else if (_account.Balance > 100 && _account.Balance < 1000)
{
_account.State = new MemberState(_account);
}
}
}

public class MemberState : AccountState
{
public MemberState(Account account)
{
_account = account;
}

public override void Deposit(double amount)
{
_account.Balance += amount;
Console.WriteLine(amount + "元，存款后的账户余额为：" + _account.Balance);
StateCheck();
}

public override void Shopping(double amount)
{
double newBalance = _account.Balance - amount;
if (newBalance > 0)
{
_account.Balance -= amount;
Console.WriteLine(amount + "元，账户余额：" + _account.Balance);
}

StateCheck();
}

public override void StateCheck()
{
if (_account.Balance > 0 && _account.Balance < 100)
{
_account.State = new VistorState(_account);
}
else if (_account.Balance > 1000)
{
_account.State = new VIPState(_account);

}
}
}
}