在Unity 4.6新增的uGUI中，可以方便地對控制元件，通過新增EventTrigger指令碼來進行新增事件。但是裡面並沒有包括長按事件，需要自己來實現長按事件。

長按事件

using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;

public class LongPressEventTrigger : UIBehaviour, IPointerDownHandler, IPointerUpHandler, IPointerExitHandler
{
    [Tooltip("How long must pointer be down on this object to trigger a long press"
 
)]
    public float durationThreshold = 1.0f;

    public UnityEvent onLongPress = new UnityEvent();

    private bool isPointerDown = false;
    private bool longPressTriggered = false;
    private float timePressStarted;

    private void Update()
    {
        if (isPointerDown && !longPressTriggered)
        {
            if
 
 (Time.time - timePressStarted > durationThreshold)
            {
                longPressTriggered = true;
                onLongPress.Invoke();
            }
        }
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        timePressStarted = Time.time;
        isPointerDown = true
 
;
        longPressTriggered = false;
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        isPointerDown = false;
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        isPointerDown = false;
    }
}

長按或點選事件

當存在長按事件，又想存在點選事件時，那麼就需要判斷是否已經執行了長按事件，已經執行了就不能再執行點選事件了，程式碼如下：

using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;

public class LongPressOrClickEventTrigger : UIBehaviour, IPointerDownHandler, IPointerUpHandler, IPointerExitHandler, IPointerClickHandler
{
    [Tooltip("How long must pointer be down on this object to trigger a long press")]
    public float durationThreshold = 1.0f;

    public UnityEvent onLongPress = new UnityEvent();
    public UnityEvent onClick = new UnityEvent();

    private bool isPointerDown = false;
    private bool longPressTriggered = false;
    private float timePressStarted;

    private void Update()
    {
        if (isPointerDown && !longPressTriggered)
        {
            if (Time.time - timePressStarted > durationThreshold)
            {
                longPressTriggered = true;
                onLongPress.Invoke();
            }
        }
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        timePressStarted = Time.time;
        isPointerDown = true;
        longPressTriggered = false;
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        isPointerDown = false;
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        isPointerDown = false;
    }

    public void OnPointerClick(PointerEventData eventData)
    {
        if (!longPressTriggered)
        {
            onClick.Invoke();
        }
    }
}