using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using System.Collections.Generic;
using UnityEngine.EventSystems;
using System;
 
public class PageView : MonoBehaviour, IBeginDragHandler, IEndDragHandler
{
 
 private ScrollRect rect;      //滑動組件 
 private float targethorizontal = 0;    //滑動的起始坐標 
 private bool isDrag = false;     //是否拖拽結(jié)束 
 private List<float> posList = new List<float>();   //求出每頁的臨界角，頁索引從0開始 
 private int currentPageIndex = -1;
 public Action<int> OnPageChanged;
 public RectTransform content;
 private bool stopMove = true;
 public float smooting = 4;  //滑動速度 
 public float sensitivity = 0;
 private float startTime;
 
 private float startDragHorizontal;
 public Transform toggleList;
 
 void Start()
 {
  rect = transform.GetComponent<ScrollRect>();
  var _rectWidth = GetComponent<RectTransform>();
  var tempWidth = ((float)content.transform.childCount * _rectWidth.rect.width);
  content.sizeDelta = new Vector2(tempWidth, _rectWidth.rect.height);
  //未顯示的長度
  float horizontalLength = content.rect.width - _rectWidth.rect.width;
  for (int i = 0; i < rect.content.transform.childCount; i++)
  {
   posList.Add(_rectWidth.rect.width * i / horizontalLength);
  }
 }
 
 void Update()
 {
  if (!isDrag && !stopMove)
  {
   startTime += Time.deltaTime;
   float t = startTime * smooting;
   rect.horizontalNormalizedPosition = Mathf.Lerp(rect.horizontalNormalizedPosition, targethorizontal, t);
   if (t >= 1)
    stopMove = true;
  }
  //Debug.Log(rect.horizontalNormalizedPosition);
 }
 
 public void pageTo(int index)
 {
  if (index >= 0 && index < posList.Count)
  {
   rect.horizontalNormalizedPosition = posList[index];
   SetPageIndex(index);
   GetIndex(index);
  }
 }
 private void SetPageIndex(int index)
 {
  if (currentPageIndex != index)
  {
   currentPageIndex = index;
   if (OnPageChanged != null)
    OnPageChanged(index);
  }
 }
 
 public void OnBeginDrag(PointerEventData eventData)
 {
  isDrag = true;
  //開始拖動
  startDragHorizontal = rect.horizontalNormalizedPosition;
 }
 
 public void OnEndDrag(PointerEventData eventData)
 {
  float posX = rect.horizontalNormalizedPosition;
  posX += ((posX - startDragHorizontal) * sensitivity);
  posX = posX < 1 ? posX : 1;
  posX = posX > 0 ? posX : 0;
  int index = 0;
 
  float offset = Mathf.Abs(posList[index] - posX);
  //Debug.Log("offset " + offset);
 
 
  for (int i = 1; i < posList.Count; i++)
  {
   float temp = Mathf.Abs(posList[i] - posX);
   //Debug.Log("temp " + temp);
   //Debug.Log("i" + i);
   if (temp < offset)
   {
    index = i;
    offset = temp;
   }
   //Debug.Log("index " + index);
  }
  //Debug.Log(index);
  SetPageIndex(index);
  GetIndex(index);
  targethorizontal = posList[index]; //設置當前坐標，更新函數(shù)進行插值 
  isDrag = false;
  startTime = 0;
  stopMove = false;
 
 }
 
 public void GetIndex(int index)
 {
  var toogle = toggleList.GetChild(index).GetComponent<Toggle>();
  toogle.isOn = true;
 }
}

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using System;
 
public class GameController : MonoBehaviour {
 [SerializeField]
 private Text pageNumber;
 [SerializeField]
 private InputField inputField;
 [SerializeField]
 private PageView pageView;
 // Use this for initialization
 void Start () {
  pageNumber.text = string.Format ("當前頁碼：0");
  pageView.OnPageChanged = pageChanged;
 }
 
 void pageChanged (int index) {
  pageNumber.text = string.Format ("當前頁碼：{0}" , index.ToString ());
 }
 
 public void onClick () {
  try {
   int idnex = int.Parse (inputField.text);
   pageView.pageTo (idnex);
  } catch(Exception ex) {
   Debug.LogWarning ("請輸入數(shù)字"+ex.ToString()); 
  }
 }
 
 void Destroy () {
  pageView.OnPageChanged = null;
 }
}