unity3d：ugui 长按按钮

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
using UnityEngine.Events;

public class RepeatButton : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IPointerExitHandler {

	public bool invokeOnce = false;//是否只调用一次
	private bool hadInvoke = false;//是否已经调用过

	public float interval = 0.1f;//按下后超过这个时间则认定为"长按"
	private bool isPointerDown = false;
	private float recordTime;

	public UnityEvent onPress = new UnityEvent();//按住时调用
	public UnityEvent onRelease = new UnityEvent();//松开时调用

    public static RepeatButton Get(Transform trans)
    {
        if (trans.GetComponent<RepeatButton>() == null)
        {
            trans.gameObject.AddComponent<RepeatButton>();
        }
        return trans.GetComponent<RepeatButton>();
    }
    void Update () 
	{
		if (invokeOnce && hadInvoke) return;
		if (isPointerDown)
		{
			if ((Time.time - recordTime) > interval)
			{
				onPress.Invoke();
				hadInvoke = true;
                recordTime = Time.time;
            }
		}
	}

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

	public void OnPointerUp(PointerEventData eventData)
	{
		isPointerDown = false;
		hadInvoke = false;
		onRelease.Invoke();
	}

	public void OnPointerExit(PointerEventData eventData)
	{
		isPointerDown = false;
		hadInvoke = false;
		onRelease.Invoke();
	}
}

RepeatButton.Get(m_trans.Find("BtnPar/BtnShang")).onPress.AddListener(()=> { OnBtnTianChe(EnTianCheDir.Shang); });