计时器

    /// <summary>
    /// 计时器
    /// </summary>
    /// <param name="seconds"></param>
    /// <param name="timeout">时间结束的回调</param>
    /// <param name="timeUpdate">时间更新的回调</param>
    /// <returns></returns>
    public static IEnumerator Timer(float seconds, Action timeout, Action<float> timeUpdate)
    {
        float time = seconds;
        while (true)
        {
            if (time < 0)
            {
                timeout();
                yield break;
            }
            else
            {
                timeUpdate(time);
            }
            time -= Time.deltaTime;
            yield return new WaitForFixedUpdate();
        }
    }