产品中经常用到加载动图，一般情况呢，我们都会根据UI设计师所给的UI图进行制作，我这里就介绍两种做法，此篇博客只是记录我怎么做的，方便我后续用，也希望能帮到大家。
第一种是让UI设计师给一张包含里所有序列帧的大图
比如：

导入到Unity中选中

再将Sprite Mode设置改成Multiple，打开Sprite Editor进行编辑

第二种是UI设计师把所有序列帧的图都给过来直接用代码实现加载

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

[RequireComponent(typeof(Image))]
public class Loading : MonoBehaviour
{
    [Tooltip("sprite")]
    public List<Sprite> sprite_frame;
    [Tooltip("帧动画播放的时间间隔")]
    public float duration = 0.1f;
    [Tooltip("循环")]
    public bool loop = false;
    [Tooltip("是否在加载中播放")]
    public bool loadplay = false;
    [Tooltip("播放完是否销毁")]
    public bool destroy = true;
    [Tooltip("延迟多少秒播放")]
    public float timeDelay = 0;
    [Tooltip("如果重复播放多少秒后播放")]
    public float playTimeEndDelay = 0;
    private float played_time;
    private bool playing = false;
    private Image img;
    private bool currentDelay = false;
    private bool currentPlayDelay = false;

    // Start is called before the first frame update
    void Start()
    {
        this.img = this.GetComponent<Image>();
        if (this.loadplay)
        {
            this.Play();
        }
    }
    public void Play()
    {
        if (this.loop)
        {
            this.Play_loop();
        }
        else
        {
            this.Play_once();
        }
    }
    public void Stop()
    {
        this.playing = false;
    }

    void Play_once()
    {
        if (this.sprite_frame.Count <= 1)
        {
            return;
        }

        if (timeDelay > 0)
        {
            currentDelay = true;
            Invoke("UpdataTimeDelayState", this.timeDelay);
        }

        this.played_time = 0;
        this.playing = true;
        this.loop = false;
    }
    void Play_loop()
    {
        if (this.sprite_frame.Count <= 1)
        {
            return;
        }

        if (timeDelay > 0)
        {
            currentDelay = true;
            Invoke("UpdataTimeDelayState", this.timeDelay);
        }

        this.played_time = 0;
        this.playing = true;
        this.loop = true;
    }
    private void UpdataTimeDelayState()
    {
        currentDelay = false;
    }
    private void UpdataPlayTimeDelayState()
    {
        currentPlayDelay = false;
    }
    // Update is called once per frame
    void Update()
    {
        if (!this.playing)
        {
            return;
        }

        if (currentDelay || currentPlayDelay)
        {
            return;
        }
        float dt = Time.deltaTime;
        this.played_time += dt;
        int index = (int)(this.played_time / this.duration);
        if (!this.loop)
        {
            if (index >= this.sprite_frame.Count)
            {
                this.playing = false;
                this.played_time = 0;
                if (destroy)
                {
                    Destroy(this.gameObject);
                }
            }
            else
            {
                this.img.sprite = this.sprite_frame[index];
            }
        }
        else
        {
            while (index >= this.sprite_frame.Count)
            {
                this.played_time -= (this.duration * this.sprite_frame.Count);
                index -= this.sprite_frame.Count;
                currentPlayDelay = true;
                Invoke("UpdataPlayTimeDelayState", this.playTimeEndDelay);
            }
            this.img.sprite = this.sprite_frame[index];
        }
    }
}