unity中 UGUI的按下、拖动接口事件的实现

时间:2023-03-09 08:31:54
unity中 UGUI的按下、拖动接口事件的实现
using UnityEngine;
using System.Collections.Generic;
using DG.Tweening;
using UnityEngine.EventSystems;
using UnityEngine.UI;
public class testUI : MonoBehaviour, IPointerClickHandler, IPointerDownHandler, IPointerUpHandler, IDragHandler, IEndDragHandler,
IPointerEnterHandler, IPointerExitHandler
{ //private GraphicRaycaster graphicRaycaster;
//private EventSystem eventSystem;
//private RectTransform Image; public RectTransform canvas; //得到canvas的ugui坐标
private RectTransform imgRect; //得到图片的ugui坐标
Vector2 offset = new Vector3(); //用来得到鼠标和图片的差值
Vector3 imgReduceScale = new Vector3(0.7f, 0.7f, ); //设置图片缩放
Vector3 imgNormalScale = new Vector3(, , ); //正常大小
void Start()
{
//graphicRaycaster = GameObject.Find("Canvas").GetComponent<GraphicRaycaster>();
//eventSystem = GameObject.Find("EventSystem").GetComponent<EventSystem>();
//Image = GameObject.Find("Canvas/Image").GetComponent<RectTransform>();
//SetRectTransformSize(Image, new Vector2(2, 2)); imgRect = GetComponent<RectTransform>();
} // Update is called once per frame
void Update()
{
//if (CheckGuiRaycastObjects()) return;
//Debug.Log(EventSystem.current.gameObject.name);
//if (Input.GetMouseButtonDown(0))
//{
// if (EventSystem.current.IsPointerOverGameObject())
// {
// Debug.Log("当前触摸在UI上");
// Debug.LogError(EventSystem.current.IsPointerOverGameObject());
// } // else
// Debug.Log("当前没有触摸在UI上");
//}
} bool CheckGuiRaycastObjects()
{
PointerEventData eventData = new PointerEventData(eventSystem);
eventData.pressPosition = Input.mousePosition;
eventData.position = Input.mousePosition; List<RaycastResult> list = new List<RaycastResult>();
graphicRaycaster.GetComponent<GraphicRaycaster>().Raycast(eventData, list);
Debug.Log(list.Count);
return list.Count > ;
} public void OnPointerClick(PointerEventData eventData)
{
//if (eventData.clickCount == 2)
//{
// this.transform.DOScale(new Vector3(1.5f, 1.5f, 1.5f), 0.5f);
//}
//if (eventData.clickCount == 1)
//{
// this.transform.DOScale(Vector3.one, 0.5f);
//}
} private void SetInsetAndSizeFromParentEdge(GameObject obj)
{
var rt = obj.gameObject.GetComponent<RectTransform>();
rt.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Right, , );
rt.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Bottom, , );
} public static void SetRectTransformSize(RectTransform trans, Vector2 newSize)
{
Vector2 oldSize = trans.rect.size;
Vector2 deltaSize = newSize - oldSize;
trans.offsetMin = trans.offsetMin - new Vector2(deltaSize.x * trans.pivot.x, deltaSize.y * trans.pivot.y);
trans.offsetMax = trans.offsetMax + new Vector2(deltaSize.x * (1f - trans.pivot.x), deltaSize.y * (1f - trans.pivot.y));
} //当鼠标按下时调用 接口对应 IPointerDownHandler
public void OnPointerDown(PointerEventData eventData)
{
Vector2 mouseDown = eventData.position; //记录鼠标按下时的屏幕坐标
Vector2 mouseUguiPos = new Vector2(); //定义一个接收返回的ugui坐标
//RectTransformUtility.ScreenPointToLocalPointInRectangle():把屏幕坐标转化成ugui坐标
//canvas:坐标要转换到哪一个物体上,这里img父类是Canvas,我们就用Canvas
//eventData.enterEventCamera:这个事件是由哪个摄像机执行的
//out mouseUguiPos:返回转换后的ugui坐标
//isRect:方法返回一个bool值,判断鼠标按下的点是否在要转换的物体上
bool isRect = RectTransformUtility.ScreenPointToLocalPointInRectangle(canvas, mouseDown, eventData.enterEventCamera, out mouseUguiPos);
if (isRect) //如果在
{
//计算图片中心和鼠标点的差值
offset = imgRect.anchoredPosition - mouseUguiPos;
}
} //当鼠标抬起时调用 对应接口 IPointerUpHandler
public void OnPointerUp(PointerEventData eventData)
{
//offset = Vector2.zero;
}
//当鼠标拖动时调用 对应接口 IDragHandler
public void OnDrag(PointerEventData eventData)
{
Vector2 mouseDrag = eventData.position; //当鼠标拖动时的屏幕坐标
Vector2 uguiPos = new Vector2(); //用来接收转换后的拖动坐标
//和上面类似
bool isRect = RectTransformUtility.ScreenPointToLocalPointInRectangle(canvas, mouseDrag, eventData.enterEventCamera, out uguiPos); if (isRect)
{
//设置图片的ugui坐标与鼠标的ugui坐标保持不变
imgRect.anchoredPosition = offset + uguiPos;
}
}
//当鼠标结束拖动时调用 对应接口 IEndDragHandler
public void OnEndDrag(PointerEventData eventData)
{
//offset = Vector2.zero;
}
//当鼠标进入图片时调用 对应接口 IPointerEnterHandler
public void OnPointerEnter(PointerEventData eventData)
{
//imgRect.localScale = imgReduceScale; //缩小图片
}
//当鼠标退出图片时调用 对应接口 IPointerExitHandler
public void OnPointerExit(PointerEventData eventData)
{
//imgRect.localScale = imgNormalScale; //回复图片
}
}