本篇文章为大家展示了Unity 中怎么利用ScrollRect实现一个无限滚动条，内容简明扼要并且容易理解，绝对能使你眼前一亮，通过这篇文章的详细介绍希望你能有所收获。
一 .总体流程
建一个循环滑动脚本 InfinityGridLayoutGroup类并且有删除刷新功能;
一个数据管理刷新脚本如：MarketLayoutGroup(商店市场数据刷新管理器)，继承InfinityGridLayoutGroup类 并且在滑动 的时候给每条数据对象赋值显示；
一个单数据对象MarketElement;
一个UI 用于显示滑动；
1 .InfinityGridLayoutGroup类:
using UnityEngine;using System.Collections;using UnityEngine.UI;using System.Collections.Generic; [RequireComponent(typeof(GridLayoutGroup))][RequireComponent(typeof(ContentSizeFitter))]public class InfinityGridLayoutGroup : MonoBehaviour{ public int minAmount = 0;//实现无限滚动，需要的最少的child数量。屏幕上能看到的+一行看不到的，比如我在屏幕上能看到 2 行，每一行 2 个。则这个值为 2行*2个 + 1 行* 2个 = 6个。 public bool changePanel = false;//切换面板 public bool up = false; RectTransform rectTransform; GridLayoutGroup gridLayoutGroup; ContentSizeFitter contentSizeFitter; ScrollRect scrollRect; List<RectTransform> children = new List<RectTransform>(); Vector2 startPosition; public int amount = 0; public delegate void UpdateChildrenCallbackDelegate(int index, Transform trans); public UpdateChildrenCallbackDelegate updateChildrenCallback = null; public int realIndex = -1; int realIndexUp = -1; //从下往上; #region // 改动 Vector2 gridLayoutSizeLast; Vector2 gridLayoutPosLast; Vector2 currentPos; #endregion public bool hasInit = false; Vector2 gridLayoutSize; Vector2 gridLayoutPos; Dictionary<Transform, Vector2> childsAnchoredPosition = new Dictionary<Transform, Vector2>(); Dictionary<Transform, int> childsSiblingIndex = new Dictionary<Transform, int>(); // Use this for initialization void Start() { StartCoroutine(InitChildren()); } IEnumerator InitChildren() { yield return 0; // Debug.Log("hasInit" + hasInit); minAmount = transform.childCount; if (!hasInit) { //childsAnchoredPosition.Clear(); //获取Grid的宽度; rectTransform = GetComponent<RectTransform>(); gridLayoutGroup = GetComponent<GridLayoutGroup>(); gridLayoutGroup.enabled = false; contentSizeFitter = GetComponent<ContentSizeFitter>(); contentSizeFitter.enabled = false; gridLayoutSizeLast = rectTransform.sizeDelta; gridLayoutPos = rectTransform.anchoredPosition; gridLayoutSize = rectTransform.sizeDelta; // Debug.Log("<Color=Red>children</Color>---" + children.Count + "realIndex---" + realIndex); //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); childsSiblingIndex.Add(child, child.GetSiblingIndex()); } //Debug.Log("<Color=Blue>children</Color>---" + children.Count + "realIndex---" + realIndex); } else { //Debug.Log("gridLayoutPosLast--" + gridLayoutSizeLast.y); rectTransform.anchoredPosition = new Vector2(gridLayoutPos.x, Vector2.zero.y); // Debug.Log("current--" + currentPos.y); rectTransform.sizeDelta = gridLayoutSize; gridLayoutSizeLast = rectTransform.sizeDelta; // Debug.Log("rectTransform.sizeDelta--" + rectTransform.sizeDelta.y); children.Clear(); realIndex = -1; realIndexUp = -1; //children重新设置上下顺序; foreach (var info in childsSiblingIndex) { info.Key.SetSiblingIndex(info.Value); } //children重新设置anchoredPosition; for (int index = 0; index < transform.childCount; index++) { Transform child = transform.GetChild(index); RectTransform childRectTrans = child.GetComponent<RectTransform>(); if (childsAnchoredPosition.ContainsKey(child)) { childRectTrans.anchoredPosition = childsAnchoredPosition[child]; } else { Debug.LogError("childsAnchoredPosition no contain " + child.name); } } } //获取所有child; for (int index = 0; index < transform.childCount; index++) { Transform trans = transform.GetChild(index); trans.gameObject.SetActive(true); children.Add(transform.GetChild(index).GetComponent<RectTransform>()); //初始化前面几个; UpdateChildrenCallback(children.Count - 1, transform.GetChild(index)); } startPosition = rectTransform.anchoredPosition; // Debug.Log("<Color=Red>children</Color>---"+ children.Count+ "realIndex---"+ realIndex); realIndex = children.Count - 1; ShowElement(realIndex); //Debug.Log( scrollRect.transform.TransformPoint(Vector3.zero)); // Debug.Log(transform.TransformPoint(children[0].localPosition)); hasInit = true; //如果需要显示的个数小于设定的个数; for (int index = 0; index < minAmount; index++) { children[index].gameObject.SetActive(index < amount); } if (gridLayoutGroup.constraint == GridLayoutGroup.Constraint.FixedColumnCount) { //如果小了一行，则需要把GridLayout的高度减去一行的高度; int row = (minAmount - amount) / gridLayoutGroup.constraintCount; if (row > 0) { rectTransform.sizeDelta -= new Vector2(0, (gridLayoutGroup.cellSize.y + gridLayoutGroup.spacing.y) * row); } } else { //如果小了一列，则需要把GridLayout的宽度减去一列的宽度; int column = (minAmount - amount) / gridLayoutGroup.constraintCount; if (column > 0) { rectTransform.sizeDelta -= new Vector2((gridLayoutGroup.cellSize.x + gridLayoutGroup.spacing.x) * column, 0); } } //if (amount <= minAmount) // scrollRect.enabled = false; //else // scrollRect.enabled = true; } void ScrollCallback(Vector2 data) { UpdateChildren(); } void UpdateChildren() { // Debug.Log("当前位置"); if (transform.childCount < minAmount) { return; } // Debug.Log("当前位置" + rectTransform.anchoredPosition.y + "startPosition.y" + startPosition.y); currentPos = rectTransform.anchoredPosition; //Vector2 currentPos = rectTransform.anchoredPosition; if (gridLayoutGroup.constraint == GridLayoutGroup.Constraint.FixedColumnCount) { float offsetY = currentPos.y - startPosition.y; if (offsetY > 0) { //向上拉，向下扩展; { if (realIndex >= amount - 1) { startPosition = currentPos; return; } up = false; float scrollRectUp = scrollRect.transform.TransformPoint(Vector3.zero).y; Vector3 childBottomLeft = new Vector3(children[0].anchoredPosition.x, children[0].anchoredPosition.y - gridLayoutGroup.spacing.y - gridLayoutGroup.cellSize.y * 0.5f, 0f); //gridLayoutGroup.cellSize.y float childBottom = transform.TransformPoint(childBottomLeft).y; if (childBottom >= scrollRectUp) { Debug.Log("childBottom >= scrollRectUp"); //移动到底部; for (int index = 0; index < gridLayoutGroup.constraintCount; index++) { children[index].SetAsLastSibling(); children[index].anchoredPosition = new Vector2(children[index].anchoredPosition.x, children[children.Count - 1].anchoredPosition.y - gridLayoutGroup.cellSize.y - gridLayoutGroup.spacing.y); realIndex++; if (realIndex > amount - 1) { children[index].gameObject.SetActive(false); } else { UpdateChildrenCallback(realIndex, children[index]); } } ShowElement(realIndex); //GridLayoutGroup 底部加长; rectTransform.sizeDelta += new Vector2(0, gridLayoutGroup.cellSize.y + gridLayoutGroup.spacing.y); gridLayoutSizeLast = rectTransform.sizeDelta; // Debug.Log("<Color=Red>gridLayoutSizeLast.y</Color>" + gridLayoutSizeLast.y); //更新child; for (int index = 0; index < children.Count; index++) { children[index] = transform.GetChild(index).GetComponent<RectTransform>(); } } // Debug.Log("realIndex向上--" + realIndex); } } else { //Debug.Log("Drag Down"); //向下拉，下面收缩; if (realIndex + 1 <= children.Count) { startPosition = currentPos; return; } RectTransform scrollRectTransform = scrollRect.GetComponent<RectTransform>(); Vector3 scrollRectAnchorBottom = new Vector3(0, -scrollRectTransform.rect.height - gridLayoutGroup.spacing.y, 0f);//- gridLayoutGroup.spacing.y float scrollRectBottom = scrollRect.transform.TransformPoint(scrollRectAnchorBottom).y; Vector3 childUpLeft = new Vector3(children[children.Count - 1].anchoredPosition.x, children[children.Count - 1].anchoredPosition.y + gridLayoutGroup.spacing.y * minAmount, 0f);//gridLayoutGroup.spacing.y realIndex-minAmount+1 float childUp = transform.TransformPoint(childUpLeft).y; //Debug.Log("childUp----" + childUp + "scrollRectBottom---" + scrollRectBottom); if (childUp < scrollRectBottom) { //Debug.Log("childUp < scrollRectBottom"); up = true; //把底部的一行 移动到顶部 for (int index = 0; index < gridLayoutGroup.constraintCount; index++) { children[children.Count - 1 - index].SetAsFirstSibling(); children[children.Count - 1 - index].anchoredPosition = new Vector2(children[children.Count - 1 - index].anchoredPosition.x, children[0].anchoredPosition.y + gridLayoutGroup.cellSize.y + gridLayoutGroup.spacing.y); children[children.Count - 1 - index].gameObject.SetActive(true); UpdateChildrenCallback(realIndex - children.Count - index, children[children.Count - 1 - index]); } realIndex -= gridLayoutGroup.constraintCount; ShowElement(realIndex); //GridLayoutGroup 底部缩短; //rectTransform.anchoredPosition = gridLayoutPos; rectTransform.sizeDelta -= new Vector2(0, gridLayoutGroup.cellSize.y + gridLayoutGroup.spacing.y); gridLayoutSizeLast = rectTransform.sizeDelta; //Debug.Log("<Color=Red>gridLayoutSizeLast.y</Color>" + gridLayoutSizeLast.y); //更新child; for (int index = 0; index < children.Count; index++) { children[index] = transform.GetChild(index).GetComponent<RectTransform>(); } } // Debug.Log("realIndex向下--" + realIndex); } } #region 左右滑动 else { float offsetX = currentPos.x - startPosition.x; if (offsetX < 0) { //向左拉，向右扩展; { if (realIndex >= amount - 1) { startPosition = currentPos; return; } float scrollRectLeft = scrollRect.transform.TransformPoint(Vector3.zero).x; Vector3 childBottomRight = new Vector3(children[0].anchoredPosition.x + gridLayoutGroup.cellSize.x, children[0].anchoredPosition.y, 0f); float childRight = transform.TransformPoint(childBottomRight).x; // Debug.LogError("childRight=" + childRight); if (childRight <= scrollRectLeft) { //Debug.Log("childRight <= scrollRectLeft"); //移动到右边; for (int index = 0; index < gridLayoutGroup.constraintCount; index++) { children[index].SetAsLastSibling(); children[index].anchoredPosition = new Vector2(children[children.Count - 1].anchoredPosition.x + gridLayoutGroup.cellSize.x + gridLayoutGroup.spacing.x, children[index].anchoredPosition.y); realIndex++; if (realIndex > amount - 1) { children[index].gameObject.SetActive(false); } else { UpdateChildrenCallback(realIndex, children[index]); } } if (realIndex >= 7) //GridLayoutGroup 右侧加长; rectTransform.sizeDelta += new Vector2(gridLayoutGroup.cellSize.x + gridLayoutGroup.spacing.x, 0); //更新child; for (int index = 0; index < children.Count; index++) { children[index] = transform.GetChild(index).GetComponent<RectTransform>(); } } } } else { //Debug.Log("Drag Down"); //向右拉，右边收缩; if (realIndex + 1 <= children.Count) { startPosition = currentPos; return; } RectTransform scrollRectTransform = scrollRect.GetComponent<RectTransform>(); Vector3 scrollRectAnchorRight = new Vector3(scrollRectTransform.rect.width + gridLayoutGroup.spacing.x, 0, 0f); float scrollRectRight = scrollRect.transform.TransformPoint(scrollRectAnchorRight).x; Vector3 childUpLeft = new Vector3(children[children.Count - 1].anchoredPosition.x, children[children.Count - 1].anchoredPosition.y, 0f); float childLeft = transform.TransformPoint(childUpLeft).x; if (childLeft >= scrollRectRight) { //Debug.LogError("childLeft > scrollRectRight"); //把右边的一行 移动到左边; for (int index = 0; index < gridLayoutGroup.constraintCount; index++) { children[children.Count - 1 - index].SetAsFirstSibling(); children[children.Count - 1 - index].anchoredPosition = new Vector2(children[0].anchoredPosition.x - gridLayoutGroup.cellSize.x - gridLayoutGroup.spacing.x, children[children.Count - 1 - index].anchoredPosition.y); children[children.Count - 1 - index].gameObject.SetActive(true); UpdateChildrenCallback(realIndex - children.Count - index, children[children.Count - 1 - index]); } //GridLayoutGroup 右侧缩短; rectTransform.sizeDelta -= new Vector2(gridLayoutGroup.cellSize.x + gridLayoutGroup.spacing.x, 0); //更新child; for (int index = 0; index < children.Count; index++) { children[index] = transform.GetChild(index).GetComponent<RectTransform>(); } realIndex -= gridLayoutGroup.constraintCount; } #endregion } } // Debug.Log("realIndex--" + realIndex); //Debug.Log("currentPos.y--" + currentPos.y + "rectTransform.sizeDelta---" + rectTransform.sizeDelta.y); startPosition = currentPos; gridLayoutPosLast = currentPos; } void UpdateChildrenCallback(int index, Transform trans) { if (updateChildrenCallback != null) { updateChildrenCallback(index, trans); } } public virtual void ShowElement(int endIndex) { } /// <summary> /// 设置总的个数; /// </summary> /// <param name="count"></param> public void SetAmount(int count) { amount = count; //如果切换面板 if (!changePanel) { //hasInit = false; StartCoroutine(InitChildren()); changePanel = true; } else { // Debug.Log("currentPos.y--" + currentPos.y); if (currentPos.y > 10) { 如果需要显示的个数小于设定的个数; //Debug.Log("minAmount--"+minAmount); for (int index = 0; index < minAmount; index++) { children[index].gameObject.SetActive(index < amount); } //删除操作 if (GameInstance.isDecrase) { if (realIndex > minAmount - 1) { realIndex--; //把底部的一行 移动到顶部 for (int index = 0; index < gridLayoutGroup.constraintCount; index++) { children[children.Count - 1 - index].SetAsFirstSibling(); children[children.Count - 1 - index].anchoredPosition = new Vector2(children[children.Count - 1 - index].anchoredPosition.x, children[0].anchoredPosition.y + gridLayoutGroup.cellSize.y + gridLayoutGroup.spacing.y); children[children.Count - 1 - index].gameObject.SetActive(true); UpdateChildrenCallback(realIndex - children.Count - index, children[children.Count - 1 - index]); } //更新child; for (int index = 0; index < children.Count; index++) { children[index] = transform.GetChild(index).GetComponent<RectTransform>(); } } GameInstance.isDecrase = false;//GameInstance类中bool变量控制条目删除的刷新使用 currentPos = new Vector2(currentPos.x, currentPos.y - gridLayoutGroup.cellSize.y - gridLayoutGroup.spacing.y); if (realIndex > minAmount - 1) { gridLayoutSizeLast = new Vector2(gridLayoutSizeLast.x, gridLayoutSizeLast.y - gridLayoutGroup.cellSize.y - gridLayoutGroup.spacing.y); } else rectTransform.anchoredPosition = currentPos; } else rectTransform.anchoredPosition = currentPos; rectTransform.sizeDelta = gridLayoutSizeLast; rectTransform.anchoredPosition = new Vector2(currentPos.x, currentPos.y); startPosition = rectTransform.anchoredPosition; ShowElement(realIndex); } else { StartCoroutine(InitChildren()); } } }}2.MarketLayoutGroup类：
using System.Collections;using System.Collections.Generic;using UnityEngine; public class MarketLayoutGroup : InfinityGridLayoutGroup{ bool isNotOutRange = false; //商店市场的可买的商品集合 private List<MarketGood> marketGoods; //可出售到商店的商品集合 public List<SealGood> marketSeal; //可要在商店加工的商品集合 private List<ExchangeGood> marketMake; //重写父类的调用循环刷新显示 public override void ShowElement(int endIndex) { //获取商店窗体对象 MarketActivity market = MainPanelContrller.Instance.presenter.MarketWindowsActivity[0] as MarketActivity; //判断当前窗体默认开启的类型是否是可买的商品集合 if (market.current == CurrentPanel.Image_Buy) { //获取可买商品的数据（ GameInstance全局数据储存脚本） marketGoods = GameInstance.marketGoods; //判断商品数 amount = marketGoods.Count; //Debug.Log ("marketGoods--"+marketGoods.Count); //endIndex为可见ui的最大下标 isNotOutRange = endIndex < marketGoods.Count ? true : false; //遍历ui对象数目 判断每一条ui应该显示的数据 并调用MarketElement赋值显示。 for (int i = 0; i < transform.childCount; i++) { //获取ui显示对象 MarketElement presenter = transform.GetChild(i).GetComponent<MarketElement>(); //判断并且赋值显示 if (isNotOutRange) { //presenter.name.text = myGoodList[endIndex - minAmount + 1 + i].name; presenter.SetData(marketGoods[endIndex - minAmount + 1 + i]); } else { if (endIndex - minAmount + 1 + i < marketGoods.Count) { presenter.SetData(marketGoods[endIndex - minAmount + 1 + i]); } else { MarketGood good = new MarketGood(); presenter.SetData(good); } } } } else if (market.current == CurrentPanel.Image_Seal) { if (GameInstance.marketSeals == null) return; //Debug.Log("GameInstance.marketSeals" + GameInstance.marketSeals.Count); // Debug.Log("marketSeal" + marketSeal); marketSeal = GameInstance.marketSeals; amount = marketSeal.Count; isNotOutRange = endIndex < marketSeal.Count ? true : false; for (int i = 0; i < transform.childCount; i++) { ElementSeal presenter = transform.GetChild(i).GetComponent<ElementSeal>(); if (isNotOutRange) { //Debug.Log("endIndex+" + endIndex); //Debug.Log(endIndex - minAmount + 1 + i); //presenter.name.text = myGoodList[endIndex - minAmount + 1 + i].name; presenter.SetData(marketSeal[endIndex - minAmount + 1 + i]); } else { // Debug.Log(endIndex - minAmount + 1 + i); if (endIndex - minAmount + 1 + i < marketSeal.Count) { presenter.SetData(marketSeal[endIndex - minAmount + 1 + i]); } else { SealGood _good = new SealGood(); presenter.SetData(_good); } } } } else { //Debug.Log("当前所在条数--" + realIndex); //加工 marketMake = GameInstance.marketMakes; amount = marketMake.Count; isNotOutRange = endIndex < marketMake.Count ? true : false; for (int i = 0; i < transform.childCount; i++) { MarketElement presenter = transform.GetChild(i).GetComponent<MarketElement>(); if (isNotOutRange) { //presenter.name.text = myGoodList[endIndex - minAmount + 1 + i].name; presenter.SetData(marketMake[endIndex - minAmount + 1 + i]); } else { //Debug.Log ("marketGoods---"+marketGoods); if (endIndex - minAmount + 1 + i < marketMake.Count) { presenter.SetData(marketMake[endIndex - minAmount + 1 + i]); } else { ExchangeGood good = new ExchangeGood(); presenter.SetData(good); } } } } }}3.UI对象父类MarketElement：
using System.Collections;using System.Collections.Generic;using UnityEngine;public class MarketElement : MonoBehaviour { public virtual void SetData(ExchangeGood good) { } public virtual void SetData(MarketGood good) { } public virtual void SetData(SealGood good) { } public virtual void SetData() { }}实现类：ElementMarket
using System.Collections;using System.Collections.Generic;using UnityEngine;using UnityEngine.UI; public class ElementMarket : MarketElement{ private MarketGood _goodData; [Header("物品框父物体")] public Image good_BG; public Text price; public Text num; public Text name; public Text nameGoods; public Button buy; LocalizeData xml_data = new LocalizeData(); string config = LocalizeManager.Instance.GetCurrentLanguage(); public override void SetData(MarketGood good) { base.SetData(good); if (good.goodsId == 0) return; _goodData = good; if (MainPanelContrller.Instance.openStyle == OpenMarketStyle.Skill) { GoodsInfoData myGood = new GoodsInfoData(); GameManager.Instance.allXmlData.GetXmlData<GoodsInfoData>(ConfigFilesName.GOODS_CONFIG, good.goodsId, ref myGood); good_BG.transform.GetChild(0).GetComponent<Image>().sprite = SpriteManager.LoadAtlasSprite("Sprite/Item", "Item_" + myGood.Icon); price.text = "x" + good.price.ToString(); nameGoods.text = myGood.Name; // num.text = "x" + good.num; // int trend = good.price - good.lastPrice; //使用描述 name.text = myGood.Description; //物品描述 num.text = myGood.Description_2; } else { //员外的 } } void OnEnable() { buy.onClick.AddListener(BuyBtn); } void OnDisable() { buy.onClick.RemoveAllListeners(); } /// <summary> /// 打开购买二级界面 /// </summary> void BuyBtn() { Debug.Log("购买了资源商店：" + _goodData.goodsId + " 物品"); this.gameObject.transform.parent.GetComponent<MarketLayoutGroup>().changePanel = true; Bundle bundle = new Bundle(); bundle.PutObject("marketGood", _goodData); MainPanelContrller.Instance.presenter.MarketWindowsActivity[0].manager.PushWindow(typeof(BuyActivity), bundle); } }UI:
滑动总UI scrollrect
滑动组件Grid MarketLayerGourp
滑动条 ElementMarket:
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