设计模式在 TypeScript 中的应用 - 策略模式

定义

实现

interface Compute {
computeF (num1: number, num2: number): number
}

// 创建策略对象
class ComputeAdd implements Compute {
public computeF (
num1: number,
num2: number
): number {
return num1 + num2
}
}

class ComputeSub implements Compute {
public computeF (
num1: number,
num2: number
): number {
return num1 - num2
}
}

class ComputeMul implements Compute {
public computeF (
num1: number,
num2: number
): number {
return num1 * num2
}
}

// 创建行为类
class Context {
public compute: Compute

public constructor (compute: Compute) {
this.compute = compute
}

public excuteCompute (
num1: number,
num2: number
): number {
return this.compute.computeF(num1, num2)
}
}

let context1 = new Context(new ComputeAdd())
.excuteCompute(1, 2)
let context2 = new Context(new ComputeSub())
.excuteCompute(1, 2)
let content3 = new Context(new ComputeMul())
.excuteCompute(1, 2)

console.log(context1, context2, content3) // 3, -1, 2

// 武器接口
interface Weapon {
useWeapon (): void
}

// 技能接口
interface Skill {
useSkill (): void
}

// 武器类
class Gun implements Weapon {
public useWeapon () {
console.log( 'Weapon: Gun')
}
}

class Stick implements Weapon {
public useWeapon () {
console.log('Weapon: Stick')
}
}

// 技能类
class Magic implements Skill {
public useSkill () {
console.log('Skill: Magic')
}
}

class Kongfu implements Skill {
public useSkill () {
console.log('Skill: Chinese Kongfu')
}
}

// 抽象类，用于给其他类继承
abstract class Way {
// 武器
public weapon: Weapon

// 技能
public skill: Skill

// 设置武器
public setWeapon (weapon: Weapon): void {
this.weapon = weapon
}

// 设置技能
public setSkill (skill: Skill): void {
this.skill = skill
}
public getWeaponAndSkill (): void {
this.weapon.useWeapon()
this.skill.useSkill()
}

// 抽象方法
public abstract saySome (): void
}

class SimpleWay extends Way {
public constructor () {
super()
this.weapon = new Gun()
this.skill = new Magic()
}

public saySome () {
console.log('屠龙宝刀，点击就送')
}
}

const way = new SimpleWay()
way.saySome()

console.log('=======')

way.getWeaponAndSkill()

console.log('=======')

way.setWeapon(new Stick)
way.setSkill(new Kongfu)
way.getWeaponAndSkill()