Unity的UnityEngine.EventSystems中的接口

一、

IPointerDownHandler,IPointerUpHandler,IPointerClickHandler,IPointerEnterHandler,IPointerExitHandler

public void OnPointerClick(PointerEventData eventData)
    {
        Debug.Log("OnPointerClick，鼠标点击，在点击之后抬起时响应");
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        Debug.Log("OnPointerDown，鼠标在UI上按下时候响应");
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        Debug.Log("OnPointerUp，鼠标在UI上抬起时候响应");
    }

    public void OnPointerEnter(PointerEventData eventData)
    {
        Debug.Log("OnPointerEnter，鼠标光标进入UI范围瞬间响应");
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        Debug.Log("OnPointerExit，鼠标光标离开UI范围瞬间响应");
    }

二、

IBeginDragHandler, IDragHandler, IEndDragHandler

public void OnBeginDrag(PointerEventData eventData)
    {
        Debug.Log("OnBeginDrag，鼠标拖动动作开始的瞬间执行一次");
    }

    public void OnDrag(PointerEventData eventData)
    {
        Debug.Log("OnDrag，鼠标拖动过程中每帧调用");
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        Debug.Log("OnEndDrag，鼠标拖动动作松开的时候调用一次");
    }

三、

IsPointerOverGameObject

public class EventSystemTest : MonoBehaviour
{
    void Update()
    {
        if (EventSystem.current.IsPointerOverGameObject())
        {
            Debug.Log("鼠标光标处在UI上方每帧调用");
        }
    }
}

四、

鼠标点击处，屏幕上一点的UI层数 EventSystem.current.RaycastAll()

//点击区域碰撞数
        public static bool IsPointerOverUIObject(Vector2 screenPosition)
        {
            PointerEventData eventDataCurrentPosition = new PointerEventData(EventSystem.current);
            eventDataCurrentPosition.position = screenPosition;
            List<RaycastResult> results = new List<RaycastResult>();
            EventSystem.current.RaycastAll(eventDataCurrentPosition, results);
            return results.Count > 5;
        }