【设计模式】第23节：行为型模式之“策略模式”

一、简介

策略模式：定义一族算法类，将每个算法分别封装起来，让它们可以互相替换。策略模式可以使算法的变化独立于使用它们的客户端（这里的客户端代指使用算法的代码）。

二、适用场景

动态选择算法
多种类似的行为

三、UML类图

请添加图片描述

四、案例

根据成年人、青年、小孩的不同计算不同的价格。

package mainimport "fmt"type PricingStrategy interface {CalculatePrice(price float64) float64
}type ChildrenPricingStrategy struct {
}func NewChildrenPricingStrategy() *ChildrenPricingStrategy {return &ChildrenPricingStrategy{}
}func (s *ChildrenPricingStrategy) CalculatePrice(price float64) float64 {return price * 0.5
}type AdultPricingStrategy struct {
}func NewAdultPricingStrategy() *AdultPricingStrategy {return &AdultPricingStrategy{}
}func (s *AdultPricingStrategy) CalculatePrice(price float64) float64 {return price
}type SeniorPricingStrategy struct {
}func NewSeniorPricingStrategy() *SeniorPricingStrategy {return &SeniorPricingStrategy{}
}func (s *SeniorPricingStrategy) CalculatePrice(price float64) float64 {return price * 0.8
}type PriceCalculator struct {Strategy PricingStrategy
}func NewPriceCalculator(strategy PricingStrategy) *PriceCalculator {return &PriceCalculator{Strategy: strategy}
}func (pc *PriceCalculator) Calculator(price float64) float64 {return pc.Strategy.CalculatePrice(price)
}func main() {calculator := NewPriceCalculator(NewChildrenPricingStrategy())fmt.Printf("Children price: %v\n", calculator.Calculator(100))calculator = NewPriceCalculator(NewAdultPricingStrategy())fmt.Printf("Adult price: %v\n", calculator.Calculator(100))calculator = NewPriceCalculator(NewSeniorPricingStrategy())fmt.Printf("Senior price: %v\n", calculator.Calculator(100))
}