UGUI之无线滚动实现
发表于2018-09-10
由于项目需要实现视频播放列表，如果一下加载过多视频资源的话，占用内存过多会出现卡死闪退现象，所以在这用到了无线滚动，用有限的UI个数去实现无数的视频播放功能。下面就来看看无线滚动实现。
下面是我开发前整理的demo结构如下图所示：
具体实现看代码：
using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using System.Collections.Generic;
[RequireComponent(typeof(GridLayoutGroup))]
[RequireComponent(typeof(ContentSizeFitter))]
public class InfinityGridLayoutGroup : MonoBehaviour
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[SerializeField]
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。
/// <summary>
/// SrollView的的RectTransform组件
/// </summary>
RectTransform rectTransform;
/// <summary>
/// GridLayoutGroup组件
/// </summary>
GridLayoutGroup gridLayoutGroup;
ContentSizeFitter contentSizeFitter;
ScrollRect scrollRect;
List<RectTransform> children=new List<RectTransform>();
Vector2 startPosition;
/// <summary>
/// Children总数
/// </summary>
int amount = 0;
/// <summary>
/// 代理事件
/// </summary>
/// <param name="index"></param>
/// <param name="trans"></param>
public delegate void UpdateChildrenCallbackDelegate(int index, Transform trans);
public UpdateChildrenCallbackDelegate updateChildrenCallback = null;
int realIndex = -1;
int realIndexUp = -1; //从下往上;
bool hasInit = false;
Vector2 gridLayoutSize;
Vector2 gridLayoutPos;
Dictionary<Transform, Vector2> childsAnchoredPosition = new Dictionary<Transform, Vector2>();
Dictionary<Transform, int> childsSiblingIndex = new Dictionary<Transform, int>();
void Start ()
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SetAmount(20);
updateChildrenCallback = UIUpdateChildrenCallback;
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/// <summary>
/// 初始化Children
/// </summary>
/// <returns></returns>
IEnumerator InitChildren()
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yield return 0;
if (!hasInit)
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//获取Grid的宽度;
rectTransform = GetComponent<RectTransform>();
//关掉GridLayoutGroup和ContentSizeFitter组件
gridLayoutGroup = GetComponent<GridLayoutGroup>();
gridLayoutGroup.enabled = false;
contentSizeFitter = GetComponent<ContentSizeFitter>();
contentSizeFitter.enabled = false;
//获取父物体锚点
gridLayoutPos = rectTransform.anchoredPosition;
//获取父物体比例
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++)
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Transform child=transform.GetChild(index);
RectTransform childRectTrans= child.GetComponent<RectTransform>();
childsAnchoredPosition.Add(child, childRectTrans.anchoredPosition);
childsSiblingIndex.Add(child, child.GetSiblingIndex());
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else
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Debug.Log("这句话不会被打印出来的。。。");
rectTransform.anchoredPosition = gridLayoutPos;
rectTransform.sizeDelta = gridLayoutSize;
children.Clear();
realIndex = -1;
realIndexUp = -1;
//children重新设置上下顺序;
foreach (var info in childsSiblingIndex)
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info.Key.SetSiblingIndex(info.Value);
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//children重新设置anchoredPosition;
for (int index = 0; index < transform.childCount; index++)
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Transform child = transform.GetChild(index);
RectTransform childRectTrans = child.GetComponent<RectTransform>();
if (childsAnchoredPosition.ContainsKey(child))
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childRectTrans.anchoredPosition = childsAnchoredPosition[child];
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else
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Debug.LogError("childsAnchoredPosition no contain "+child.name);
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//获取所有child;
for (int index = 0; index < transform.childCount; index++)
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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));
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startPosition = rectTransform.anchoredPosition;
realIndex = children.Count - 1;
//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++)
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children[index].gameObject.SetActive(index < amount);
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if (gridLayoutGroup.constraint == GridLayoutGroup.Constraint.FixedColumnCount)
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//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)
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rectTransform.sizeDelta -= new Vector2(0, (gridLayoutGroup.cellSize.y + gridLayoutGroup.spacing.y) * row);
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else
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//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)
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rectTransform.sizeDelta -= new Vector2((gridLayoutGroup.cellSize.x + gridLayoutGroup.spacing.x) * column, 0);
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/// <summary>
/// Scroll滚动回调
/// </summary>
/// <param name="data"></param>
void ScrollCallback(Vector2 data)
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UpdateChildren();
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/// <summary>
/// 滚动回调事件
/// </summary>
void UpdateChildren()
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Debug.Log("进入回调事件");
if (transform.childCount < minAmount)
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return;
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//得到父物体的锚点位置
Vector2 currentPos = rectTransform.anchoredPosition;
//父物体的
if (gridLayoutGroup.constraint == GridLayoutGroup.Constraint.FixedColumnCount)
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float offsetY = currentPos.y - startPosition.y;
if (offsetY > 0)
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//向上拉，向下扩展;
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if (realIndex >= amount - 1)
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startPosition = currentPos;
return;
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float scrollRectUp = scrollRect.transform.TransformPoint(Vector3.zero).y;
Vector3 childBottomLeft = new Vector3(children[0].anchoredPosition.x, children[0].anchoredPosition.y - gridLayoutGroup.cellSize.y, 0f);
float childBottom = transform.TransformPoint(childBottomLeft).y;
if (childBottom >= scrollRectUp)
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//Debug.Log("childBottom >= scrollRectUp");
//移动到底部;
for (int index = 0; index < gridLayoutGroup.constraintCount; index++)
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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)
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children[index].gameObject.SetActive(false);
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else
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UpdateChildrenCallback(realIndex, children[index]);
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//GridLayoutGroup 底部加长;
rectTransform.sizeDelta += new Vector2(0, gridLayoutGroup.cellSize.y + gridLayoutGroup.spacing.y);
//更新child;
for (int index = 0; index < children.Count; index++)
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children[index] = transform.GetChild(index).GetComponent<RectTransform>();
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else
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//Debug.Log("Drag Down");
//向下拉，下面收缩;
if (realIndex + 1 <= children.Count)
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startPosition = currentPos;
return;
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RectTransform scrollRectTransform = scrollRect.GetComponent<RectTransform>();
Vector3 scrollRectAnchorBottom = new Vector3(0, -scrollRectTransform.rect.height - gridLayoutGroup.spacing.y, 0f);
float scrollRectBottom = scrollRect.transform.TransformPoint(scrollRectAnchorBottom).y;
Vector3 childUpLeft = new Vector3(children[children.Count - 1].anchoredPosition.x, children[children.Count - 1].anchoredPosition.y, 0f);
float childUp = transform.TransformPoint(childUpLeft).y;
if (childUp < scrollRectBottom)
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//Debug.Log("childUp < scrollRectBottom");
//把底部的一行 移动到顶部
for (int index = 0; index < gridLayoutGroup.constraintCount; index++)
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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]);
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realIndex -= gridLayoutGroup.constraintCount;
//GridLayoutGroup 底部缩短;
rectTransform.sizeDelta -= new Vector2(0, gridLayoutGroup.cellSize.y + gridLayoutGroup.spacing.y);
//更新child;
for (int index = 0; index < children.Count; index++)
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children[index] = transform.GetChild(index).GetComponent<RectTransform>();
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else
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float offsetX = currentPos.x - startPosition.x;
if (offsetX < 0)
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//向左拉，向右扩展;
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if (realIndex >= amount - 1)
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startPosition = currentPos;
return;
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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)
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//Debug.Log("childRight <= scrollRectLeft");
//移动到右边;
for (int index = 0; index < gridLayoutGroup.constraintCount; index++)
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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)
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children[index].gameObject.SetActive(false);
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else
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UpdateChildrenCallback(realIndex, children[index]);
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//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++)
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children[index] = transform.GetChild(index).GetComponent<RectTransform>();
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else
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//Debug.Log("Drag Down");
//向右拉，右边收缩;
if (realIndex + 1 <= children.Count)
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startPosition = currentPos;
return;
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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)
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//Debug.LogError("childLeft > scrollRectRight");
//把右边的一行 移动到左边;
for (int index = 0; index < gridLayoutGroup.constraintCount; index++)
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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]);
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//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++)
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children[index] = transform.GetChild(index).GetComponent<RectTransform>();
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realIndex -= gridLayoutGroup.constraintCount;
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startPosition = currentPos;
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/// <summary>
/// Children文字显示变化
/// </summary>
/// <param name="index"></param>
/// <param name="trans"></param>
void UpdateChildrenCallback(int index,Transform trans)
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if (updateChildrenCallback != null)
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updateChildrenCallback(index, trans);
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void UIUpdateChildrenCallback(int index, Transform trans)
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Debug.Log("UpdateChildrenCallback: index=" + index + " name:" + trans.name);
Text text = trans.Find("Text").GetComponent<Text>();
text.text = index.ToString();
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/// <summary>
/// 设置总的个数;
/// </summary>
/// <param name="count"></param>
public void SetAmount(int count)
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amount = count;
StartCoroutine(InitChildren());
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设置GridLayout Group的Constraint控制每行的或者每列的个数
Min Amount设置初始化的个数。
来自：https://blog.csdn.net/weixin_39706943/article/details/80853746