Unity新的UI系统的监听事件的用法有很多种，在UGUI刚出来的时候，网上也搜到过很多种用法，今天我就把这几种方法整理一下，分享给大家。文章源自大腿Plus-https://www.shijunzh.com/archives/772
首先，是第一种方法，也是最直接简单粗暴的方法，但是这种方法只能在UI系统上使用，就是直接在UI组件上绑定事件，这个效率是最高的，但也是最麻烦的。要一个一个的去拖拽脚本到组件上。这个方法不光是Button组件，其他组件也会可以使用，比如InputField等。文章源自大腿Plus-https://www.shijunzh.com/archives/772
第二种方法也是比较简单粗暴的，但是相对事件功能上要强大的多，也不依赖组件本身，也可以使用在非UI的GameObject上，这种方法如果用在非UI的物体上，需要在主相机上添加一个PhysicRaycaster组件才能使用。文章源自大腿Plus-https://www.shijunzh.com/archives/772
第三种方法就是用代码动态的给组件加监听事件，这种方法其实和第一种原理是一样的。都是利用组件本身的事件接口去实现相应事件的方法，只不过是用代码实现的动态添加的事件监听。文章源自大腿Plus-https://www.shijunzh.com/archives/772
下面是放个按钮的添加监听事件的方法，其中一个是带参数的添加方法。文章源自大腿Plus-https://www.shijunzh.com/archives/772
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class Test : MonoBehaviour
{
Button btn1;
Button btn2;
// Use this for initialization
void Start()
{
btn1 = GetComponent<Button>();
btn1.onClick.AddListener(OnClick1);
btn2 = GetComponent<Button>();
btn2.onClick.AddListener(delegate () { OnClick2(btn2.gameObject); });
}
// Update is called once per frame
void Update()
{
}
public void OnClick1()
{
Debug.Log("Click");
}
public void OnClick2(GameObject go)
{
Debug.Log(go);
}
}
第四种方法是和第二种方法的原理是一样的，和第三种方法的实现方式是一样的，在这里也就不多说了，下面直接放上代码。下面代码是用拓展的方式写的，如果单独用可以自行提取相应代码。文章源自大腿Plus-https://www.shijunzh.com/archives/772
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using UnityEngine.UI;
public static class Develop
{
public static void AddEventTrigger(this GameObject obj, EventTriggerType eventType, UnityAction<BaseEventData> myFunction)
{
EventTrigger eventTrigger = obj.GetComponent<EventTrigger>();
if (eventTrigger == null)
{
eventTrigger = obj.AddComponent<EventTrigger>();
eventTrigger.triggers = new List<EventTrigger.Entry>();
}
UnityAction<BaseEventData> callback = new UnityAction<BaseEventData>(myFunction);
EventTrigger.Entry entry = new EventTrigger.Entry();
entry.eventID = eventType;
entry.callback.AddListener(callback);
eventTrigger.triggers.Add(entry);
}
public static void RemoveEventTrigger(this GameObject obj)
{
EventTrigger eventTrigger = obj.GetComponent<EventTrigger>();
if (eventTrigger == null)
{
return;
}
eventTrigger.triggers.Clear();
}
public static void AddEventTrigger(this Image obj, EventTriggerType eventType, UnityAction<BaseEventData> myFunction)
{
EventTrigger eventTrigger = obj.GetComponent<EventTrigger>();
if (eventTrigger == null)
{
eventTrigger = obj.gameObject.AddComponent<EventTrigger>();
eventTrigger.triggers = new List<EventTrigger.Entry>();
}
UnityAction<BaseEventData> callback = new UnityAction<BaseEventData>(myFunction);
EventTrigger.Entry entry = new EventTrigger.Entry();
entry.eventID = eventType;
entry.callback.AddListener(callback);
eventTrigger.triggers.Add(entry);
}
public static void RemoveEventTrigger(this Image obj)
{
EventTrigger eventTrigger = obj.gameObject.GetComponent<EventTrigger>();
if (eventTrigger == null)
{
return;
}
eventTrigger.triggers.Clear();
}
public static void AddEventTrigger(this RawImage obj, EventTriggerType eventType, UnityAction<BaseEventData> myFunction)
{
EventTrigger eventTrigger = obj.GetComponent<EventTrigger>();
if (eventTrigger == null)
{
eventTrigger = obj.gameObject.AddComponent<EventTrigger>();
eventTrigger.triggers = new List<EventTrigger.Entry>();
}
UnityAction<BaseEventData> callback = new UnityAction<BaseEventData>(myFunction);
EventTrigger.Entry entry = new EventTrigger.Entry();
entry.eventID = eventType;
entry.callback.AddListener(callback);
eventTrigger.triggers.Add(entry);
}
public static void RemoveEventTrigger(this RawImage obj)
{
EventTrigger eventTrigger = obj.gameObject.GetComponent<EventTrigger>();
if (eventTrigger == null)
{
return;
}
eventTrigger.triggers.Clear();
}
}
最后一种方法，是根据NGUI的UIEventListener衍生出来的，用起来也是比较方便的，这个方法是在雨松大大的博客里看到的，我做了一写整理和修改。把一些常用的事件和相应的参数调整了一下，并且可以用在非UI的物体上。文章源自大腿Plus-https://www.shijunzh.com/archives/772
using UnityEngine;
using UnityEngine.EventSystems;
public class UIEventListener: EventTrigger
{
public delegate void VoidDelegate(GameObject go);
public delegate void VectorDelegate(GameObject go, Vector2 screenPosition);
public delegate void BoolDelegate(GameObject go, bool value);
public VoidDelegate onClick;
public VoidDelegate onDown;
public VoidDelegate onUp;
public BoolDelegate onHover;
public VectorDelegate onBeginDrag;
public VectorDelegate onDrag;
public VectorDelegate onEndDrag;
static public UIEventListener Get(GameObject go)
{
PhysicsRaycaster raycaster = Camera.main.gameObject.GetComponent<PhysicsRaycaster>();
if (raycaster == null) raycaster = Camera.main.gameObject.AddComponent<PhysicsRaycaster>();
UIEventListener listener = go.GetComponent<UIEventListener>();
if (listener == null) listener = go.AddComponent<UIEventListener>();
return listener;
}
public override void OnPointerClick(PointerEventData eventData)
{
if (onClick != null) onClick.Invoke(gameObject);
}
public override void OnPointerDown(PointerEventData eventData)
{
if (onDown != null) onDown.Invoke(gameObject);
}
public override void OnPointerUp(PointerEventData eventData)
{
if (onUp != null) onUp.Invoke(gameObject);
}
public override void OnPointerEnter(PointerEventData eventData)
{
if (onHover != null) onHover.Invoke(gameObject, true);
}
public override void OnPointerExit(PointerEventData eventData)
{
if (onHover != null) onHover.Invoke(gameObject, false);
}
public override void OnBeginDrag(PointerEventData eventData)
{
Vector2 position;
Canvas canvas = FindObjectOfType<Canvas>();
RectTransform rect = canvas.GetComponent<RectTransform>();
if (RectTransformUtility.ScreenPointToLocalPointInRectangle(rect, eventData.position, canvas.worldCamera, out position))
{
if (onBeginDrag != null) onBeginDrag.Invoke(gameObject, position);
}
}
public override void OnDrag(PointerEventData eventData)
{
Vector2 position;
Canvas canvas = FindObjectOfType<Canvas>();
RectTransform rect = canvas.GetComponent<RectTransform>();
if (RectTransformUtility.ScreenPointToLocalPointInRectangle(rect, eventData.position, canvas.worldCamera, out position))
{
if (onDrag != null) onDrag.Invoke(gameObject, position);
}
}
public override void OnEndDrag(PointerEventData eventData)
{
Vector2 position;
Canvas canvas = FindObjectOfType<Canvas>();
RectTransform rect = canvas.GetComponent<RectTransform>();
if (RectTransformUtility.ScreenPointToLocalPointInRectangle(rect, eventData.position, canvas.worldCamera, out position))
{
if (onEndDrag != null) onEndDrag.Invoke(gameObject, position);
}
}
}
文章源自大腿Plus-https://www.shijunzh.com/archives/772 
评论