用的是Animation的动画 所以动画Debug模式下的Legacy选项要勾上。

using UnityEngine;
using System.Collections;
public class Test : MonoBehaviour {
    private Animation libai;
    void Start () {
        libai = gameObject.GetComponent ();
        PlayAni ();
    }
    void PlayAni(){
        libai ["test"].time = 0;
        libai ["test"].speed = 1;
        libai.Play ();
        StartCoroutine ("PlayBack");
    }
    IEnumerator PlayBack(){
        yield return new WaitForSeconds (2);
        libai ["test"].time = libai ["test"].clip.length;
        libai ["test"].speed = -1;
        libai.Play ();
    }
}