Unity ugui 的 Button 组件的 点击、按下、抬起等按钮事件（eventTrigger）

using UnityEngine;
using UnityEngine.EventSystems;


public class EventTriggerDelegateExample : MonoBehaviour
{
    void Start()
    {
        EventTrigger trigger = GetComponent<EventTrigger>();
        EventTrigger.Entry entry = new EventTrigger.Entry();
        entry.eventID = EventTriggerType.PointerDown;
        entry.callback.AddListener((data) => { OnPointerDownDelegate((PointerEventData)data); });
        trigger.triggers.Add(entry);
    }

    public void OnPointerDownDelegate(PointerEventData data)
    {
        Debug.Log("OnPointerDownDelegate called.");
    }
}