unity 无限循环滚动列表 请给出详细代码

以下是一个基本的Unity无限循环滚动列表的代码示例：

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class InfiniteScroll : MonoBehaviour
{
    public RectTransform prefab;
    public RectTransform content;
    public int itemCount = 10;
    public float itemHeight = 100f;

    private List<RectTransform> items = new List<RectTransform>();
    private Vector2 contentSize;
    private int firstVisibleIndex;
    private int lastVisibleIndex;

    private void Start()
    {
        contentSize = new Vector2(content.rect.width, itemCount * itemHeight);
        content.sizeDelta = contentSize;

        for (int i = 0; i < itemCount; i++)
        {
            RectTransform item = Instantiate(prefab);
            item.SetParent(content);
            item.anchoredPosition = new Vector2(0f, -i * itemHeight);
            items.Add(item);
        }

        firstVisibleIndex = 0;
        lastVisibleIndex = itemCount - 1;
    }

    private void Update()
    {
        int newFirstVisibleIndex = firstVisibleIndex;
        int newLastVisibleIndex = lastVisibleIndex;

        // Check if first item is out of view
        while (items[newFirstVisibleIndex].anchoredPosition.y + itemHeight < 0f)
        {
            items[newFirstVisibleIndex].anchoredPosition += new Vector2(0f, itemCount * itemHeight);
            newFirstVisibleIndex = (newFirstVisibleIndex + 1) % itemCount;
            newLastVisibleIndex = (newLastVisibleIndex + 1) % itemCount;
        }

        // Check if last item is out of view
        while (items[newLastVisibleIndex].anchoredPosition.y > contentSize.y - itemHeight)
        {
            items[newLastVisibleIndex].anchoredPosition -= new Vector2(0f, itemCount * itemHeight);
            newFirstVisibleIndex = (newFirstVisibleIndex - 1 + itemCount) % itemCount;
            newLastVisibleIndex = (newLastVisibleIndex - 1 + itemCount) % itemCount;
        }

        // Update visible items
        if (newFirstVisibleIndex != firstVisibleIndex || newLastVisibleIndex != lastVisibleIndex)
        {
            for (int i = 0; i < itemCount; i++)
            {
                if (i >= newFirstVisibleIndex && i <= newLastVisibleIndex)
                {
                    items[i].gameObject.SetActive(true);
                }
                else
                {
                    items[i].gameObject.SetActive(false);
                }
            }

            firstVisibleIndex = newFirstVisibleIndex;
            lastVisibleIndex = newLastVisibleIndex;
        }
    }
}

这个脚本使用了一个预制体来实例化列表项，然后在运行时将它们添加到一个RectTransform的content中。在Update()函数中，该脚本检测哪些列表项当前是可见的，然后根据需要将它们的位置更新为循环滚动列表的下一页。这个示例假设所有的列表项都具有相同的高度，但它可以轻松地修改为支持不同的高度。