设计模式_访问者模式

访问者模式

介绍

设计模式	定义	案例	问题堆积在哪里
访问模式	访问模式是行为型设计模式从对象中分类出算法这些算法封装为对象，这样这些算法类很容易扩展，添加新的算法类就可以了	不同的VIP用户在不同的节日领取不同的礼物	if else太多

解决办法	小技巧
枚举出不同的用户类（有一个相同的基类）枚举出不同的节日类（有一个相同的基类）节日访问者被不同VIP等级用户访问根据不同的用户给出不同的礼物	if else。。。转为重载函数方式函数重载（类型1）函数重载（类型2） ... 传入不同的数据类型，触发不同的重置函数

类图

代码

PlayerVipBase


public abstract class PlayerVipBase
{
    public string name;
}

PlayerVipSun


public class PlayerVipSun : PlayerVipBase
{
    public PlayerVipSun()
    {
        name = "VipSun";   
    }
}

PlayerVipMoon


public class PlayerVipMoon : PlayerVipBase
{
    public PlayerVipMoon()
    {
        name = "VipMoon "; 
    }
}

PlayerVipStar


public class PlayerVipStar : PlayerVipBase
{
    public PlayerVipStar()
    {
        name = "VipStar";
    }
}

FestivalBase


interface FestivalBase 
{
    string GetGift(PlayerVipStar player);
    string GetGift(PlayerVipMoon player);
    string GetGift(PlayerVipSun player);
}

Festival_YuanXiaoJie


public class Festival_YuanXiaoJie : FestivalBase
{
    public string GetGift(PlayerVipStar player)
    {
        return player.name + "领取了元宵节礼物:" + "66个复活币";
    }

    public string GetGift(PlayerVipMoon player)
    {
        return player.name + "领取了元宵节礼物:" + "可爱汤圆时装";
    }

    public string GetGift(PlayerVipSun player)
    {
        return player.name + "领取了元宵节礼物:" + "SSR汤圆宝宝";
    }
}

Festival_GuoQingJie


public class Festival_GuoQingJie : FestivalBase
{
    public string GetGift(PlayerVipStar player)
    {
        return player.name + "领取了国庆节礼物:" + "100R";
    }

    public string GetGift(PlayerVipMoon player)
    {
        return player.name + "领取了国庆节礼物:" + "2023国庆时装";
    }

    public string GetGift(PlayerVipSun player)
    {
        return player.name + "领取了国庆节礼物:" + "SSR龙神";
    }
}

Festival_61


public class Festival_61 : FestivalBase
{
    public string GetGift(PlayerVipStar player)
    {
        return player.name + "领取了儿童节礼物:" + "100QB";
    }

    public string GetGift(PlayerVipMoon player)
    {
        return player.name + "领取了儿童节礼物:" + "61时装";
    }

    public string GetGift(PlayerVipSun player)
    {
        return player.name + "领取了儿童节礼物:" + "SSR凤凰宝宝";
    }
}

测试代码

using UnityEngine;

public class TestFWZ : MonoBehaviour
{
    void Start()
    {
        // 不同Vip 等级的玩家
        PlayerVipStar player1  = new PlayerVipStar();
        PlayerVipMoon player2 = new PlayerVipMoon();
        PlayerVipSun player3 = new PlayerVipSun();

        // 六一儿童节
        Festival_61 liuYi = new Festival_61();
        // 国庆节
        Festival_GuoQingJie GuoQingJie = new Festival_GuoQingJie();
        // 元宵节
        Festival_YuanXiaoJie YuanXiaoJie = new Festival_YuanXiaoJie();

        // 领取奖励：61儿童节
        Debug.Log(liuYi.GetGift(player1));
        Debug.Log(liuYi.GetGift(player2));
        Debug.Log(liuYi.GetGift(player3));
        Debug.Log("------------------------");


        // 领取奖励：国庆
        Debug.Log(GuoQingJie.GetGift(player1));
        Debug.Log(GuoQingJie.GetGift(player2));
        Debug.Log(GuoQingJie.GetGift(player3));
        Debug.Log("------------------------");


        // 领取奖励：国庆
        Debug.Log(YuanXiaoJie.GetGift(player1));
        Debug.Log(YuanXiaoJie.GetGift(player2));
        Debug.Log(YuanXiaoJie.GetGift(player3));
    }
}