unity序列帧的实现。包括三种效果，后续再补充

效果1：从头播放到尾
效果2：重复播放
效果3：正放、倒放交替播放

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class XuLieZhen : MonoBehaviour
{
   
    [Header("序列帧路径")]
    public string Path;
    [Header("更换间隔")]
    public float time = 0.01f;
    float delTime;
    [Header("是否循环播放")]
    bool IsLoop;
    [Header("从第几张开始循环")]
    public int LoopIndex;
    [Header("来回效果，勾选isloop无效")]
    bool IsPingPang;
    int index = 0;
    List<Sprite> sprites = new List<Sprite>();
    bool IsPlay