Unity 无限滚动条 自己写的记录一下
content 需要和 Scroll View 宽高一致 其他情况自行修改

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

public class mScrollView : MonoBehaviour, IBeginDragHandler, IEndDragHandler, IDragHandler
{
    public delegate void OnIndexChange(int index);
    public OnIndexChange onIndexChange;

    public GameObject Item;
    public int ItemCount;
    public float spacing;

    private ScrollRect scrollRect;
    private List<Vector2> ItemPos = new List<Vector2>();
    private int Index = 0;
    private bool move = false;
    private RectTransform[] goArray = new RectTransform[3];
    private float time = 1f;
    private float inputy = 0;
    private Vector2 itemSizData;
    private Color[] colors = new Color[3] { Color.red, Color.yellow, Color.green };


    void Start()
    {
        scrollRect = GetComponent<ScrollRect>();
        itemSizData = ((RectTransform)Item.transform).sizeDelta;
        float y = itemSizData.y * ItemCount + ItemCount * spacing - spacing;
        scrollRect.content.sizeDelta = new Vector2(0, y);

        for (int i = 0; i < ItemCount; i++)
        {
            ItemPos.Add(new Vector2(0, -scrollRect.content.rect.y / 2 - itemSizData.y / 2 - (itemSizData.y + spacing) * i));
        }
        for (int i = 0; i < goArray.Length; i++)
        {
            GameObject go = GameObject.Instantiate(Item, scrollRect.content);
            go.SetActive(true);
            go.name = i.ToString();
            goArray[i] = (RectTransform)go.transform;
            goArray[i].anchoredPosition = ItemPos[i];
            go.GetComponent<Image>().color = colors[i];
        }
    }

    public void OnBeginDrag(PointerEventData eventData)
    {
        inputy = Input.mousePosition.y;
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        if (inputy > Input.mousePosition.y)
        {
            if (Index > 0)
            {
                Index--;
            }
        }
        else
        {
            if (Index < ItemCount - 1)
            {
                Index++;
            }
        }
        if (onIndexChange != null) onIndexChange(Index);

        move = true;
        Debug.Log(Index);

    }

    public void OnDrag(PointerEventData eventData)
    {
        if (inputy > Input.mousePosition.y)
        {
            int x = Index;
            if (x < 2) return;
            for (int i = 0; i < goArray.Length; i++)
            {
                if (goArray[i].anchoredPosition.y < ItemPos[Index].y - itemSizData.y / 2)
                {
                    goArray[i].anchoredPosition = ItemPos[x - 2];
                    Debug.Log("向下");
                    break;
                }
            }
        }
        else if (inputy < Input.mousePosition.y)
        {
            int x = Index + 1;
            if (x > ItemCount - 2) return;
            for (int i = 0; i < goArray.Length; i++)
            {
                if (goArray[i].anchoredPosition.y > ItemPos[Index].y + itemSizData.y / 2)
                {
                    goArray[i].anchoredPosition = ItemPos[x + 1];
                    Debug.Log("向上");
                    break;
                }
            }

        }
    }




    void Update()
    {
        if (move)
        {
            float Toy = (itemSizData.y + spacing) * Index;
            scrollRect.content.localPosition = Vector2.Lerp(scrollRect.content.localPosition, new Vector2(0, Toy), time);// (scrollRect.verticalNormalizedPosition, Toy, time);
            if (Vector2.Distance(scrollRect.content.localPosition, new Vector2(0, Toy)) < 1f)
            {
                move = false;
                scrollRect.content.localPosition = new Vector2(0, Toy);
            }
        }
    }
}