02.策略模式

class Context { Strategy strategy; public Context(Strategy strategy) { this.strategy = strategy; } //上下文接口 public void ContextInterface() { strategy.AlgorithmInterface(); } }

ConcreteStrategyB

AlgorithmInterface()

打折销售计算销售金额()

满减销售计算销售金额()

结算策略基类计算销售金额()

示例：

public abstract class CashStrategy { public abstract decimal GetSaleMoney(ShoppingCart shoppingCart); }

策略模式：

Strategy

public class CashContext { private readonly CashStrategy _casher; public CashContext(CashStrategy cash) { _casher = cash; } public decimal GetResult(ShoppingCart shoppingCart) { return _casher.GetSaleMoney(shoppingCart); } }

ConcreteStrategyC

ConcreteStrategyA

它定义了算法家族，分别封装起来，让他们直接可以相互替换，此模式让算法的变化，不会影响到使用算法的客户。

策略上下文属性：_销售策略基类引用对象方法：计算销售金额(){ _销售策略基类引用对象.计算销售金额()}

Context

Strategy _strategy

ConcreteInterface()

正常销售计算销售金额()

定义所有算法的公共接口

public class CashNormal : CashStrategy { public override decimal GetSaleMoney(ShoppingCart shoppingCart) { return shoppingCart.Count * shoppingCart.Price; } }