给UI元素自定义事件

 public void AddButtonDownAndScaleLisenter(AniType aniType)
    {

//获取EventTrigger 

        EventTrigger trigger = gameObject.GetComponent<EventTrigger>();

        if (trigger == null)
            trigger = gameObject.AddComponent<EventTrigger>();

        EventTrigger.Entry entry = new EventTrigger.Entry();

//添加鼠标事件        

        entry.eventID = EventTriggerType.PointerDown;

        //添加回调

        entry.callback = new EventTrigger.TriggerEvent();

        entry.callback.AddListener(delegate(BaseEventData baseEventData) {
            //action(baseEventData);
            Sequence seq = DOTween.Sequence();
            if (aniType == AniType.ToBig)
            {
                seq.Append(gameObject.GetComponent<RectTransform>().DOScale(new Vector3(1.05f, 1.05f, 0), 0.2f));
            }
            else {
                seq.Append(gameObject.GetComponent<RectTransform>().DOScale(new Vector3(0.95f, 0.95f, 0), 0.2f));
            }
        });


        trigger.triggers.Add(entry);

    }