Unity实现ScrollView滑动吸附功能

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
using DG.Tweening;
using DG.Tweening.Core.Easing;
using UnityEngine.Experimental.UIElements;

public class ScorllViewAutoHandler : MonoBehaviour, IEndDragHandler, IBeginDragHandler, IDragHandler
{
 private GameObject Scroll;
 private ScrollRect sc;
 private float OriginPosX;
 private float offsetX;
 private int CurIndex;
 private bool isDragging = false;
 private bool TimerFlag = false;
 private float Timer;
 // Start is called before the first frame update
 void Start()
 {
 CurIndex = 0;
 Scroll = this.gameObject;
 sc = Scroll.transform.parent.transform.parent.gameObject.GetComponent<ScrollRect>();
 }
 public void OnEndDrag(PointerEventData eventData)
 {
 int tempIndex=0;
 sc.OnEndDrag(eventData);
 offsetX = this.transform.localPosition.x - OriginPosX;
 if (Mathf.Abs(offsetX) % 450 < 225)
 {
  tempIndex = (int)(Mathf.Abs(offsetX) / 450);
  int _TempTargetIndex = 0;
  if (offsetX <0)
  {
  _TempTargetIndex = CurIndex + tempIndex;
  }
  else
  {
  _TempTargetIndex = CurIndex - tempIndex;
  }
  if (_TempTargetIndex >= 0 && _TempTargetIndex <= Scroll.transform.childCount - 1)
  {
  _TempTargetIndex = _TempTargetIndex;
  }
  else if (_TempTargetIndex < 0)
  {
  _TempTargetIndex = 0;
  }
  else
  {
  _TempTargetIndex = Scroll.transform.childCount - 1;
  }
  Debug.LogError("本次位移目标" + _TempTargetIndex + "初始" + CurIndex);
  this.transform.DOLocalMoveX(_TempTargetIndex*450, 0.5f).SetEase(Ease.OutBack);
 }
 else
 {
  tempIndex = (int)(Mathf.Abs(offsetX) / 450);
  tempIndex += 1;
  int _TempTargetIndex = 0;
  if (offsetX < 0)
  {
  _TempTargetIndex = CurIndex + tempIndex;
  }
  else
  {
  _TempTargetIndex = CurIndex - tempIndex;
  }
  if (_TempTargetIndex >= 0 && _TempTargetIndex <= Scroll.transform.childCount - 1)
  {
  _TempTargetIndex = _TempTargetIndex;
  }
  else if (_TempTargetIndex < 0)
  {
  _TempTargetIndex = 0;
  }
  else
  {
  _TempTargetIndex = Scroll.transform.childCount - 1;
  }
  Debug.LogError("本次位移目标" + _TempTargetIndex + "初始" + CurIndex);
  this.transform.DOLocalMoveX(_TempTargetIndex*450, 0.5f).SetEase(Ease.OutBack);
 }
 }

 public void OnBeginDrag(PointerEventData eventData)
 {
 sc.OnBeginDrag(eventData);
 OriginPosX = this.transform.localPosition.x;
 CurIndex = (int)(Mathf.Abs(this.transform.localPosition.x) / 450);
 offsetX = 0;
 //当鼠标在A对象按下并开始拖拽时 A对象响应此事件
 // 此事件在OnInitializePotentialDrag之后响应 OnDrag之前响应
 //Debug.Log("OnBeginDrag " );
 }

 public void OnDrag(PointerEventData eventData)
 {
 sc.OnDrag(eventData);
 //Debug.LogError("Dragging" );
 }
}