轮巡循环-使用模运算确保不越界

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

public class SelectCover : MonoBehaviour
{
    [SerializeField] Button left_But;
    [SerializeField] Button right_But;
    [SerializeField] Image image;
    [SerializeField] List<Sprite> cover_Sprite;
    int index = 0; // 初始化为0而不是-1

    void Start()
    {
        left_But.onClick.AddListener(() => {
            index--;
            // 处理负值情况
            if (index < 0)
            {
                index = cover_Sprite.Count - 1;
            }
            image.sprite = cover_Sprite[index];
            Debug.Log($"index : " + index);
        });

        right_But.onClick.AddListener(() => {
            index++;
            // 使用模运算确保不越界
            index %= cover_Sprite.Count;
            image.sprite = cover_Sprite[index];
            Debug.Log($"index : " + index);
        });
    }
}