unity 循环选择器

我们经会遇到点击上一个按钮选择上一个物体，点击下一个按钮选择下一个物体，这种需求，因此整理了一个通用类

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// 循环选择器
/// </summary>
public class LoopSelecter<T>
{
    
    /// <summary>
    /// 所有的物体
    /// </summary>
    public List<T> objs = new List<T>();
    /// <summary>
    /// 上一个按钮
    /// </summary>
    /// </summary>
    public Button lastBtn;
    /// <summary>
    /// 下一个按钮
    /// </summary>
    public Button nextBtn;
    /// <summary>
    /// 当前的页码
    /// </summary>
    public int index = 0;
    /// <summary>
    /// 每页的数量
    /// </summary>
    public int onePageNum;
    /// <summary>
    /// 回调函数 参数1 当前选中的物体 参数2 索引
    /// </summary>
    public System.Action<T, int> act;

    /// <summary>
    /// 构造函数 参数1 2 向前按钮 向后按钮 参数3 所有的循环物体 参数4 初始索引 默认为0
    /// </summary>
    public LoopSelecter(Button lastBtn, Button nextBtn, List<T> objs,int onePageNum = 1,int startIndex = 0)
    {
    
        this.onePageNum = onePageNum;
        index = startIndex;
        //注册上一个按钮
        if (lastBtn != null)
        {
    
            this.lastBtn = lastBtn;
            this.lastBtn.onClick.AddListener(() =>
            {
    
                ChangeSelect_One(false);
            });
        }
        //注册下一个按钮
        if (nextBtn != null)
        {
    
            this.nextBtn = nextBtn;
            this.nextBtn.onClick.AddListener(() =>
            {
    
                ChangeSelect_One(true);
            });
        }

        //放入物体列表
        for (int i = 0; i < objs.Count; i++)
        {
    
            this.objs.Add(objs[i]);
        }
    }

    /// <summary>
    /// 切换 单个
    /// </summary>
    /// <param name="isNext"></param>
    public T ChangeSelect_One(bool isNext)
    {
    
        if (isNext)
        {
    
            index += 1;
            if (index >= objs.Count)
            {
    
                index = 0;
            }
        }
        else
        {
    
            index -= 1;
            if (index < 0)
            {
    
                index = objs.Count - 1;
            }
        }
        act?.Invoke(objs[index], index);
        return objs[index];
    }
    /// <summary>
    /// 获取当前的物体
    /// </summary>
    /// <returns></returns>
    public T GetCurrentObj()
    {
    
        return objs[index];
    }
    /// <summary>
    /// 根据索引获取一个物体
    /// </summary>
    /// <returns></returns>
    public T GetObjByIndex(int index)
    {
    
        return objs[index];
    }
    /// <summary>
    /// 获取当前的索引
    /// </summary>
    public int GetCurrentIndex()
    {
    
        return index;
    }
    /// <summary>
    /// 重置索引 并返回第一个值
    /// </summary>
    /// <returns></returns>
    public T ResetIndex()
    {
    
        index = 0;
        return objs[index];
    }

}

使用示例，示例化一个上述脚本的对象

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// 音乐盒面板，处理面板的逻辑
/// </summary>
public class JukeboxPanel : PanelBase
{
     
    /// <summary>
    /// 循环选择器
    /// </summary>
    private LoopSelecter<Sprite> loopSelecter;

    public Button lastBtn;
    public Button nextBtn;
    /// <summary>
    /// 图片的集合
    /// </summary>
    public List<Sprite> spriteList = new List<Sprite>();
    /// <summary>
    /// 展示用的图片
    /// </summary>
    private Image image;
    /// <summary>
    /// 提示的文本框
    /// </summary>
    private Text tipText;
    /// <summary>
    /// 提示语句
    /// </summary>
    public List<string> tipList;


    private void Awake()
    {
    
        image = transform.Find("Container/TipPanel/Image").GetComponent<Image>();
        tipText = transform.Find("Container/TipPanel/TipText").GetComponent<Text>();

        loopSelecter = new LoopSelecter<Sprite>(lastBtn, nextBtn,spriteList);
        loopSelecter.act += (obj, index) =>
        {
    
            ResetTipOnEnable(obj as Sprite, tipList[index]);
        };
    } 
    /// <summary>
    /// 重设提示面板
    /// </summary>
    private void ResetTipOnEnable(Sprite sprite,string tip)
    {
    
        image.sprite = sprite;
        tipText.text = tip;
    }
}