UGUI 无限循环列表
LoopScrollView 脚本
将该脚本挂在 scrollRect 上
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
public class LoopScrollView : MonoBehaviour
{
public enum Direction
{
None,
Vertical,
Horizontal,
}
private enum ItemDirection
{
Top,
Center,
Bottom,
}
private class ScrollItem
{
public int V_Index;
public GameObject gameObject;
/// <summary>
/// 是否可见
/// </summary>
private bool m_bVisible = false;
public bool V_bVisible
{
get => m_bVisible;
set
{
if (gameObject != null && gameObject.activeSelf != value)
gameObject.SetActive(value);
m_bVisible = value;
}
}
public ScrollItem(GameObject obj) => gameObject = obj;
}
public delegate void ItemLoad(GameObject obj, int index);
[SerializeField] private ScrollRect m_ScrollRect;
[SerializeField, Header("为空时默认为 ScrollRect 的 Content")] private RectTransform m_Content;
[SerializeField, Header("顶部边距")] private float m_TopDistance = 0;
[SerializeField, Header("格子大小")] private Vector2 m_CellSize;
[SerializeField, Header("间距")] private Vector2 m_Spacing;
[SerializeField, Header("一行个数")] private int m_SplitNum = 1;
[SerializeField, Header("默认和ScrollRect 相同")] private Direction m_Direction = Direction.None;
[SerializeField, Header("最后一行是否铺满")] private bool m_bBespread = false;
[SerializeField, Header("物品")] private GameObject m_Item;
private bool m_bInit = false;
/// <summary>
/// 最大创建元素个数
/// </summary>
private int m_MaxItem = 0;
/// <summary>
/// 元素个数
/// </summary>
private int m_Count;
/// <summary>
/// scrollRect content 展示范围 滑动方向的长度
/// </summary>
private float m_ScrollLength;
private float m_ContentLength;
/// <summary>
/// 屏幕未满时不需要滚动
/// </summary>
private bool m_bNeedScroll = false;
/// <summary>
/// 最后一次展示的索引范围
/// </summary>
private int m_StartIndex = 0;
private int m_EndIndex = -1;
private ItemLoad OnItemLoadHandler;
private List<ScrollItem> m_ItemList;
private void Awake()
{
if (m_ScrollRect == null)
m_ScrollRect = GetComponent<ScrollRect>();
if (m_Content == null && m_ScrollRect != null)
m_Content = m_ScrollRect.content;
}
private void OnEnable()
{
if(m_ScrollRect)
m_ScrollRect.onValueChanged.AddListener(OnUpdate);
}
private void OnDisable()
{
if (m_ScrollRect)
m_ScrollRect.onValueChanged.RemoveListener(OnUpdate);
}
#region 接口
public void F_Init()
{
if (m_bInit)
return;
if (m_ScrollRect == null || m_Item == null)
return;
if (m_Direction == Direction.None)
m_Direction = m_ScrollRect.vertical ? Direction.Vertical : Direction.Horizontal;
Vector2 size = m_ScrollRect.GetComponent<RectTransform>().sizeDelta;
m_ScrollLength = m_Direction == Direction.Vertical ? size.y : size.x;
m_MaxItem = m_SplitNum * (Mathf.CeilToInt(m_ScrollLength / (m_Direction==Direction.Vertical?(m_CellSize.y + m_Spacing.y) :(m_CellSize.x + m_Spacing.x))) + 1);
m_ItemList = new List<ScrollItem>(m_MaxItem);
m_bInit = true;
}
/// <summary>
/// 设置加载回调
/// </summary>
/// <param name="load"></param>
public void F_SetOnItemLoadHandler(ItemLoad load)
{
OnItemLoadHandler = load;
}
public void F_SetItemCount(int count)
{
m_Count = count;
SetContentSize();
MoveItem(0, ItemDirection.Top);
OnUpdate(true);
}
public void F_AddItem(int count = 1)
{
m_Count += count;
SetContentSize();
UpdateVisible(m_StartIndex, m_EndIndex, true);
}
public void F_DelItem(int count = 1)
{
m_Count -= count;
SetContentSize();
float pos = m_Direction == Direction.Vertical ? m_Content.anchoredPosition.y : -m_Content.anchoredPosition.x;
if(pos > m_ContentLength - m_ScrollLength)
SetContentPos(m_ContentLength - m_ScrollLength);
OnUpdate(true);
}
public void F_SetItemTop(int index)
{
if (MoveItem(index, ItemDirection.Top))
OnUpdate();
}
public void F_SetItemCenter(int index)
{
if (MoveItem(index, ItemDirection.Center))
OnUpdate();
}
public void F_SetItemBottom(int index)
{
if (MoveItem(index, ItemDirection.Bottom))
OnUpdate();
}
/// <summary>
/// 全部更新
/// </summary>
public void F_UpdateItem()
{
UpdateVisible(m_StartIndex, m_EndIndex, true);
}
public void F_Clear()
{
UpdateVisible(0, -1, false);
MoveItem(0, ItemDirection.Top);
m_Count = 0;
}
public void F_StopMovement()
{
if (m_ScrollRect)
m_ScrollRect.StopMovement();
}
/// <summary>
/// 返回所有显示的
/// </summary>
/// <typeparam name="T"></typeparam>
/// <returns></returns>
public List<T> F_GetAllItem<T>() where T : MonoBehaviour
{
List<T> list = new List<T>();
ScrollItem item;
for (int i = 0; i < m_ItemList.Count; i++)
{
item = m_ItemList[i];
if (item.V_bVisible && item.gameObject.GetComponent<T>() != null)
list.Add(item.gameObject.GetComponent<T>());
}
return list;
}
/// <summary>
/// 遍历执行事件
/// 不想全部更新的时候用
///
/// 道具全部更新可能会更新道具id，图标，数量等
/// 这个方法直接返回脚本，里面的方法任意选择调用
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="action"></param>
public void F_ForeachAllItem<T>(System.Action<T, int> action)
{
if (action == null)
return;
ScrollItem item;
for (int i = 0; i < m_ItemList.Count; i++)
{
item = m_ItemList[i];
if (item.V_bVisible && item.gameObject.GetComponent<T>() != null)
action(item.gameObject.GetComponent<T>(), item.V_Index);
}
}
#endregion
/// <summary>
/// 滑动时更新
/// </summary>
/// <param name="v"></param>
private void OnUpdate(Vector2 v)
{
if(m_bNeedScroll)
OnUpdate();
}
private void OnUpdate(bool isReset = false)
{
if (!m_bInit)
return;
int start, end;
int last = m_Count % m_SplitNum;
if (m_Count != 0 && m_bNeedScroll)
{
float pos, cellSize, spacingSize;
if (m_Direction == Direction.Vertical)
{
pos = m_Content.anchoredPosition.y;
cellSize = m_CellSize.y;
spacingSize = m_Spacing.y;
}
else
{
pos = -m_Content.anchoredPosition.x;
cellSize = m_CellSize.x;
spacingSize = m_Spacing.x;
}
// 滑到最上面
if (pos <= 0 || pos - m_TopDistance <= 0)
start = 0;
// 滑到最下面 最后一行如果不满 就不需要显示最上面的几个
else if (pos >= m_ContentLength - m_ScrollLength)
start = Mathf.Max(0, m_Count - m_MaxItem + (last == 0 ? 0 : m_SplitNum - last));
// 滑动在中间
else
start = Mathf.FloorToInt((pos - m_TopDistance) / (cellSize + spacingSize)) * m_SplitNum;
}
else
{
start = 0;
}
end = Mathf.Min(start + m_MaxItem, m_Count + (!m_bBespread || last == 0 ? 0 : m_SplitNum - last)) - 1;
UpdateVisible(start, end, isReset);
}
/// <summary>
/// 更新可见
/// </summary>
/// <param name="start"></param>
/// <param name="end"></param>
private void UpdateVisible(int start, int end, bool isReset)
{
ScrollItem item;
int add = end - start + 1 - m_ItemList.Count;
// 创建的 item 不够用 先补上
if (add > 0)
{
for (int i = 0; i < add; i++)
{
m_ItemList.Add(CreateItem());
}
}
int index = start;
if (index >= m_StartIndex && index <= m_EndIndex)
index = m_EndIndex + 1;
for (int i = 0; i < m_ItemList.Count; i++)
{
item = m_ItemList[i];
if (item.V_bVisible && item.V_Index >= start && item.V_Index <= end)
{
if (isReset)
OnItemLoadHandler?.Invoke(item.gameObject, item.V_Index);
}
else
{
if (index <= end)
{
item.V_Index = index;
item.V_bVisible = true;
SetItemPos(item);
OnItemLoadHandler?.Invoke(item.gameObject, item.V_Index);
index++;
if (index >= m_StartIndex && index <= m_EndIndex)
index = m_EndIndex + 1;
}
else
{
item.V_bVisible = false;
}
}
}
m_StartIndex = start;
m_EndIndex = end;
}
private ScrollItem CreateItem()
{
GameObject obj = GameObject.Instantiate(m_Item);
obj.transform.SetParent(m_Content);
obj.transform.localScale = m_Item.transform.localScale;
obj.GetComponent<RectTransform>().anchoredPosition3D = Vector3.zero;
return new ScrollItem(obj);
}
/// <summary>
/// 设置 滑动高度
/// </summary>
private void SetContentSize()
{
int len = m_Count / m_SplitNum + (m_Count % m_SplitNum != 0 ? 1 : 0);
if (m_Direction == Direction.Vertical)
{
m_ContentLength = m_TopDistance + len * m_CellSize.y + (len - 1) * m_Spacing.y;
m_Content.sizeDelta = new Vector2(m_Content.sizeDelta.x, Mathf.Max(m_ScrollLength, m_ContentLength));
}
else
{
m_ContentLength = m_TopDistance + len * m_CellSize.x + (len - 1) * m_Spacing.x;
m_Content.sizeDelta = new Vector2(Mathf.Max(m_ScrollLength, m_ContentLength), m_Content.sizeDelta.y);
}
m_bNeedScroll = m_ContentLength > m_ScrollLength;
}
/// <summary>
/// 滑动到 item 位置
/// </summary>
/// <param name="index"></param>
/// <param name="itemDirection"></param>
/// <returns></returns>
private bool MoveItem(int index, ItemDirection itemDirection)
{
if (!m_bInit)
return false;
Vector2 v = GetItemPos(index);
float p;
// 竖向 y 坐标是负值
switch (itemDirection)
{
case ItemDirection.Top:
p = m_Direction == Direction.Vertical ? -v.y - m_CellSize.y / 2 : v.x - m_CellSize.x / 2;
break;
case ItemDirection.Center:
p = m_Direction == Direction.Vertical ? -v.y - m_ScrollLength / 2 : -v.x - m_ScrollLength / 2;
break;
case ItemDirection.Bottom:
p = m_Direction == Direction.Vertical ? -v.y + m_CellSize.y / 2 - m_ScrollLength : v.x + m_CellSize.x / 2 - m_ScrollLength;
break;
default:
p = 0;
break;
}
p = Mathf.Clamp(p, 0, m_ContentLength - m_ScrollLength);
SetContentPos(p);
return true;
}
/// <summary>
/// 滑动到某个位置
/// </summary>
/// <param name="pos"></param>
private void SetContentPos(float pos)
{
if (m_Direction == Direction.Vertical)
m_Content.anchoredPosition = new Vector2(m_Content.anchoredPosition.x, pos);
else
m_Content.anchoredPosition = new Vector2(-pos, m_Content.anchoredPosition.y);
F_StopMovement();
}
/// <summary>
/// 设置位置
/// </summary>
/// <param name="item"></param>
private void SetItemPos(ScrollItem item)
{
item.gameObject.GetComponent<RectTransform>().anchoredPosition = GetItemPos(item.V_Index);
}
private Vector2 GetItemPos(int index)
{
// 第 line 行 第 num 个
int line = index / m_SplitNum;
int num = index % m_SplitNum;
float x, y;
bool bOdd = m_SplitNum % 2 == 1;
float w;
if (m_Direction == Direction.Vertical)
{
w = m_CellSize.x + m_Spacing.x;
// 竖着 y 坐标递减，x 坐标从左往右递增
y = -(m_TopDistance + m_CellSize.y / 2 + line * m_CellSize.y + line * m_Spacing.y);
if (bOdd)
x = (num - m_SplitNum / 2) * w;
else
x = (num - (m_SplitNum - 1) / 2f) * w;
}
else
{
w = m_CellSize.y + m_Spacing.y;
// 横着 x 坐标递增，y 坐标从上到下递减
x = m_TopDistance + m_CellSize.x / 2 + line * m_CellSize.x + line * m_Spacing.x;
if (bOdd)
y = (m_SplitNum / 2 - num) * w;
else
y = ((m_SplitNum - 1) / 2f - num) * w;
}
return new Vector2(x, y);
}
void OnValidate()
{
if (!Application.isPlaying && gameObject.activeInHierarchy && m_Content != null)
{
List<RectTransform> list = new List<RectTransform>();
for(int i = 0; i < m_Content.childCount; i++)
{
RectTransform t = (RectTransform)m_Content.GetChild(i);
if (t && t.gameObject.activeInHierarchy)
list.Add(t);
}
for (int i = 0; i < list.Count; i++)
{
list[i].anchoredPosition = GetItemPos(i);
}
}
}
}