使用ScrollRect制作翻页

1.标准的层级结构 ScrollRect->ViewPort->Content，Viewport负责显示区域的大小一般和Mask一起配合使用，Content使用Layout来布局，如果想使用代码来自动定位显示位置需要在Content加上Content size filter.
2.ScrollRectHelper
  1 using UnityEngine;
  2 using UnityEngine.UI;
  3 using UnityEngine.EventSystems;
  4 using System.Collections.Generic;
  5 using System;
  6 
  7 public class ScrollRectHelper : MonoBehaviour, IBeginDragHandler, IEndDragHandler
  8 {
  9     // 滑动速度
 10     public float smooting = 5;
 11 
 12     // 每页显示的项目
 13     [SerializeField]
 14     private int countPerPage = 10;
 15 
 16     ScrollRect srect;
 17     // 总页数
 18     float totalPages;
 19     // 是否拖拽结束
 20     bool isDrag = false;
 21     // 总页数索引比列 0-1
 22     List<float> listPageValue = new List<float> { 0 };
 23     // 滑动的目标位置
 24     public float targetPos = 0;
 25     // 当前位置索引
 26     float nowindex = 0;                                 
 27 
 28     void Awake()
 29     {
 30         srect = GetComponent<ScrollRect>();
 31     }
 32 
 33     public string PageText()
 34     {
 35         return (nowindex + 1) + "/" + (totalPages + 1);
 36     }
 37 
 38     // 计算每页比例
 39     public void CalcListPageValue<T>() where T : MonoBehaviour
 40     {
 41         T[] items = srect.content.GetComponentsInChildren<T>();
 42         srect.content.rect.Set(srect.content.rect.width / 2, srect.content.rect.y, srect.content.rect.width, srect.content.rect.height);
 43         totalPages = (int)(Math.Ceiling((float)items.Length / countPerPage) - 1);
 44         if (items.Length != 0)
 45         {
 46             for (float i = 1; i <= totalPages; i++)
 47             {
 48                 //Debug.Log(i / totalPages);
 49                 listPageValue.Add((i / totalPages));
 50             }
 51         }
 52     }
 53 
 54     void Update()
 55     {
 56         if (!isDrag)
 57         {
 58             srect.horizontalNormalizedPosition = Mathf.Lerp(srect.horizontalNormalizedPosition, targetPos,
 59                 Time.deltaTime * smooting);
 60         }
 61 
 62         // Debug
 63         if (Input.GetKeyDown(KeyCode.LeftArrow)) PressLeft();
 64         if (Input.GetKeyDown(KeyCode.RightArrow)) PressRight();
 65     }
 66 
 67     /// <summary>
 68     /// 拖动开始
 69     /// </summary>
 70     /// <param name="eventData"></param>
 71     public void OnBeginDrag(PointerEventData eventData)
 72     {
 73         isDrag = true;
 74     }
 75 
 76     /// <summary>
 77     /// 拖拽结束
 78     /// </summary>
 79     /// <param name="eventData"></param>
 80     public void OnEndDrag(PointerEventData eventData)
 81     {
 82         isDrag = false;
 83         var tempPos = srect.horizontalNormalizedPosition; //获取拖动的值
 84         var index = 0;
 85         float offset = Mathf.Abs(listPageValue[index] - tempPos);    //拖动的绝对值
 86         for (int i = 1; i < listPageValue.Count; i++)
 87         {
 88             float temp = Mathf.Abs(tempPos - listPageValue[i]);
 89             if (temp < offset)
 90             {
 91                 index = i;
 92                 offset = temp;
 93             }
 94         }
 95         targetPos = listPageValue[index];
 96         nowindex = index;
 97     }
 98 
 99     public void PressLeft()
100     {
101         nowindex = Mathf.Clamp(nowindex - 1, 0, totalPages);
102         targetPos = listPageValue[Convert.ToInt32(nowindex)];
103     }
104 
105     public void PressRight()
106     {
107         nowindex = Mathf.Clamp(nowindex + 1, 0, totalPages);
108         targetPos = listPageValue[Convert.ToInt32(nowindex)];
109     }
110 }