协程coroutine 二、常用的几种coroutine操作_yield return new waitforfixedupdate

1、yield return null：等到下一帧继续执行

2、yield return newwaitforendofframe：这帧结束后继续执行

3、yield return newwaitforfixedupdates：等到下一物理帧后执行

4、yield return newwaitforseconds：N秒后继续执行。实际应用：定时器。当然，也可以使用update和invoke来实现定时器

5、yield return www：开启WWW的异步下载，直到下载完毕后继续执行

6、yield coroutine：等待另一个协程，实现协程的串联，如游戏的引导步骤

7、yield break：终止掉yield迭代逻辑并跳出协程

yield return www

    private string url = "http://pic14.nipic.com/20110522/7411759_164157418126_2.jpg";
    public RawImage image;
 
    void Start()
    {
        StartCoroutine(LoadImage());
    }
 
    IEnumerator LoadImage()
    {
        WWW www = new WWW(url);
        yield return www;
 
        if (www != null && string.IsNullOrEmpty(www.error))
        {
            image.texture = www.texture;
        }
    }

yield coroutine协程串联

串联几个持续性逻辑：控制角色先导航到某一处，然后做某个动作，做完动作后再导航到另一处

    NavMeshAgent agent;
    Animator anim;
 
    void Start()
    {
        agent = GetComponent<NavMeshAgent>();
        anim = GetComponent<Animator>();
 
        StartCoroutine(Work());
    }
 
    IEnumerator Work()
    {
        yield return StartCoroutine(MoveToDes(new Vector3(9, 0, 6)));
        yield return StartCoroutine(PlayAnim("Jump"));
        yield return StartCoroutine(MoveToDes(new Vector3(19, 0, 8)));
    }
 
    IEnumerator MoveToDes(Vector3 des)
    {
        agent.SetDestination(des);
        while (agent.remainingDistance > 0.01)
        {
            yield return null;
        }
    }
 
    IEnumerator PlayAnim(string name)
    {
        anim.Play(name);
        while (anim.GetCurrentAnimatorStateInfo(0).IsName(name))
        {
            yield return null;
        }
    }