Unity中实现带缓冲池的Listview（buffer listview）

这里有更完善的版本
- 实测实现了一个10000条数据的Listview，sony z3真机瞬间完成初始化，滑动无比流畅。
- 下面的截图是实际项目中使用的效果，实例化三个cellPrefab作为缓冲池，改变它们的位置和数据填充来模拟一个数据长度为15的listview：

• 下面直接给出完整代码，函数命名简明，希望大家能看明白：

using UnityEngine;
using UnityEngine.UI;
using System.Collections;
using UnityEngine.EventSystems;
using System;
using System.Collections.Generic;
using Framework;
using DG.Tweening;

//create by YJX
public class AListView : LayoutGroup
{
    private float visualDIA;

    private int eachBufferCount;

    private ScrollRect scrollRect;

    private RectTransform scrollRectTransform;

    [HideInInspector]
    private Vector2[] cellSizes;

    private List<IndexAndBuffer>[] buffersArray;

    private List<IndexAndPos> cellsPosInfo = new List<IndexAndPos>();

    private List<int> showingCells = new List<int>();//index

    public Action OnDataFillCompleted;

    [SerializeField]
    private ListViewAdapter _adapter;

    private float width;

    private float height;

    public GameObject[] prefabs;

    public string mainCellname;

    private float[] fixedHeightArray;

    private int CellsCount
    {
        get
        {
            return this.Adapter.GetCount();
        }
    }

    public bool isManualFill = false;

    public float bufferFactor = 1f;

    public ListViewAdapter Adapter
    {
        get
        {
            return _adapter;
        }
        set
        {
            _adapter = value;
            if (isManualFill && this.gameObject.activeInHierarchy == true && Application.isPlaying)
            {
                _adapter.aListview = this;
                if (isManualFill)
                {
                    Adapter.Initialize();

                    Initialize();
                }
            }
        }
    }

    // Use this for initialization
    protected override void Start()
    {
        if (this.Adapter != null && !isManualFill && Application.isPlaying)
        {
            Adapter.Initialize();

            Initialize();
        }
    }

    public void Initialize(Action onComplete = null)
    {
        if (mainCellname != string.Empty)
        {
            string[] difCell = mainCellname.Split(',');
            for (int i = 0; i < difCell.Length; i++)
            {
                prefabs[i] = Resources.Load<GameObject>(difCell[i]);
            }
        }

        this.scrollRectTransform = transform.parent.GetComponent<RectTransform>();

        this.scrollRect = this.scrollRectTransform.GetComponent<ScrollRect>();

        this.fixedHeightArray = new float[this.CellsCount];

        this.width = this.scrollRectTransform.sizeDelta.x;
        this.height = this.scrollRectTransform.sizeDelta.y;

        this.cellSizes = new Vector2[this.prefabs.Length];
        for (int i = 0; i < this.prefabs.Length; i++)
        {
            RectTransform cellRect = this.prefabs[i].GetComponent<RectTransform>();
            this.cellSizes[i] = cellRect.sizeDelta;
        }