实现原理：动态改变GUItexture的宽度。

 

 

  

EnemyInfo enemyInfo;    public GUITexture enemyBoxGUI;    private Texture enemyBox;    private Texture enemyHp;    private int currentHp;    private float hpLength;    // Use this for initialization    void Start ()    {    enemyInfo=gameObject.transform.parent.GetComponent
     
      ();    enemyBox=enemyBoxGUI.texture;    enemyHp=guiTexture.texture;    currentHp=enemyInfo.Health();    hpLength=enemyHp.width/3;      }    // Update is called once per frame    void Update ()    {        print(currentHp);        Vector3 pos=Camera.mainCamera.WorldToViewportPoint(transform.parent.position);        enemyBoxGUI.transform.position=new Vector3(pos.x-0.05f,pos.y,pos.z-0.2f);        guiTexture.transform.position=new Vector3(pos.x-0.05f,pos.y,pos.z-0.2f);        enemyBoxGUI.pixelInset=new Rect(10,20,enemyBox.width/6,enemyBox.height/8);        guiTexture.pixelInset=new Rect(10,25,hpLength*currentHp/enemyInfo.AllHealth,enemyHp.height/3);        currentHp=enemyInfo.Health();    }
     

实现效果：