UGUI 滚动优化之 隐藏视口外的GameObject

更新

添加异步创建的支持

从Github下载

https://github.com/ThisisGame/AutoHideGridLayoutGroup

上篇中，使用动态创建 Item 的方式来解决数据太多造成滚动卡顿的问题，但是实际测试发现效果不明显，于是今天修改为 滚动的时候，动态判断每个Item 是否在视口范围内，如果在范围内就显示，如果在不在视口范围内就 隐藏掉这个Item的子节点。实测效果明显。

实现的效果如下

转自http://blog.csdn.net/huutu http://www.thisisgame.com.cn

源代码如下

/************************** * 文件名:AutoHideGridLayoutGroup.cs; * 文件描述:超出ScrollRect的部分隐藏; * 创建日期:2016/0602; * Author:ThisisGame; * Page:https://github.com/ThisisGame/AutoHideGridLayoutGroup ***************************/using UnityEngine;using System.Collections;using UnityEngine.UI;using System.Collections.Generic;using System;namespace ThisisGame{    public class AutoHideGridLayoutGroup : MonoBehaviour    {        public Action<Transform, bool> onShow = null;        RectTransform rectTransform;        GridLayoutGroup gridLayoutGroup;        ScrollRect scrollRect;        List<RectTransform> children = new List<RectTransform>();        Vector2 startPosition;        Vector2 gridLayoutSize;        Vector2 gridLayoutPos;        Dictionary<Transform, Vector2> childsAnchoredPosition = new Dictionary<Transform, Vector2>();        // Use this for initialization        public void Init()        {            rectTransform = GetComponent<RectTransform>();            gridLayoutGroup = GetComponent<GridLayoutGroup>();            gridLayoutPos = rectTransform.anchoredPosition;            gridLayoutSize = rectTransform.sizeDelta;            //注册ScrollRect滚动回调;            scrollRect = transform.parent.GetComponent<ScrollRect>();            scrollRect.onValueChanged.AddListener((data) => { ScrollCallback(data); });            //获取所有child anchoredPosition 以及 SiblingIndex;            for (int index = 0; index < transform.childCount; index++)            {                Transform child = transform.GetChild(index);                RectTransform childRectTrans = child.GetComponent<RectTransform>();                childsAnchoredPosition.Add(child, childRectTrans.anchoredPosition);            }            //获取所有child;                        for (int index = 0; index < transform.childCount; index++)            {                children.Add(transform.GetChild(index).GetComponent<RectTransform>());            }            startPosition = rectTransform.anchoredPosition;        }        public void Clear()        {            if (scrollRect!=null)            {                scrollRect.onValueChanged.RemoveAllListeners();            }            if (childsAnchoredPosition != null)            {                childsAnchoredPosition.Clear();            }            if (children != null)            {                children.Clear();            }            onShow = null;        }        void ScrollCallback(Vector2 data)        {            Vector2 currentPos = rectTransform.anchoredPosition;            float offsetY = currentPos.y - startPosition.y;            startPosition = currentPos;                        if (scrollRect.vertical)            {                RectTransform scrollRectTrans = scrollRect.GetComponent<RectTransform>();                float scrollRectUp = scrollRect.transform.TransformPoint(new Vector3(0, scrollRectTrans.rect.height * (1 - scrollRectTrans.pivot.y))).y;                RectTransform scrollRectTransform = scrollRect.GetComponent<RectTransform>();                Vector3 scrollRectAnchorBottom = new Vector3(0, -scrollRectTransform.rect.height - gridLayoutGroup.spacing.y, 0f);                float scrollRectBottom = scrollRect.transform.TransformPoint(scrollRectAnchorBottom+ new Vector3(0, scrollRectTrans.rect.height * (1 - scrollRectTrans.pivot.y))).y;                for (int childindex = 0; childindex < children.Count; childindex++)                {                    Vector3 childBottomLeft = new Vector3(children[childindex].anchoredPosition.x, children[childindex].anchoredPosition.y + (1-children[childindex].pivot.y) * children[childindex].rect.height - gridLayoutGroup.cellSize.y, 0f);                    float childBottom = transform.TransformPoint(childBottomLeft).y;                    Vector3 childUpLeft = new Vector3(children[childindex].anchoredPosition.x, children[childindex].anchoredPosition.y + (1-children[childindex].pivot.y) * children[childindex].rect.height, 0f);                    float childUp = transform.TransformPoint(childUpLeft).y;                    if (childBottom <= scrollRectUp && childUp >= scrollRectBottom)                    {                        if (onShow != null)                        {                            onShow(children[childindex], true);                        }                    }                    else                    {                        if (onShow != null)                        {                            onShow(children[childindex], false);                        }                    }                }            }            else            {                RectTransform scrollRectTransform = scrollRect.GetComponent<RectTransform>();                float scrollRectLeft = scrollRect.transform.TransformPoint(new Vector3(0-scrollRectTransform.rect.width*(scrollRectTransform.pivot.x), 0,0)).x;                                Vector3 scrollRectAnchorRight = new Vector3(scrollRectTransform.rect.width + gridLayoutGroup.spacing.x, 0, 0f);                float scrollRectRight = scrollRect.transform.TransformPoint(scrollRectAnchorRight- new Vector3(scrollRectTransform.rect.width * (scrollRectTransform.pivot.x), 0)).x;                for (int childindex = 0; childindex < children.Count; childindex++)                {                    Vector3 childBottomRight = new Vector3(children[childindex].anchoredPosition.x - (children[childindex].pivot.x )* children[childindex].rect.width + gridLayoutGroup.cellSize.x, children[childindex].anchoredPosition.y, 0f);                    float childRight = transform.TransformPoint(childBottomRight).x;                    Vector3 childUpLeft = new Vector3(children[childindex].anchoredPosition.x -(children[childindex].pivot.x) * children[childindex].rect.width, children[childindex].anchoredPosition.y, 0f);                    float childLeft = transform.TransformPoint(childUpLeft).x ;                    if (childRight >= scrollRectLeft && childLeft <= scrollRectRight)                    {                        if (onShow != null)                        {                            onShow(children[childindex], true);                        }                    }                    else                    {                        if (onShow != null)                        {                            onShow(children[childindex], false);                        }                    }                }            }        }    }}

使用方法及实例下载

https://github.com/ThisisGame/AutoHideGridLayoutGroup