unity 基于scrollRect实现翻页显示

unity 基于scrollRect实现翻页显示，并定为到某一页，而不是某一页的中间方法（第二个脚本采用实际位置计算，并在update里实现平滑过渡）：

组场景时，经常需要获取鼠标（或者点击）开始结束时讯息（包括开始拖动时的事件以及对应的坐标），unity为我们提供了两个接口来实现相关方法之前在Unity基础命令中也提到过。

在此在重申一下，两个接口对应两个方法，即可以对应开始结束拖动时的事件，数据则为eventData中。

 public void OnBeginDrag(PointerEventData eventData)

public void OnEndDrag(PointerEventData eventData)

public class NewMove : MonoBehaviour,IBeginDragHandler,IEndDragHandler {

    private ScrollRect scrollRect;
    public Toggle[] toggleArr;
    //存储特定的位置坐标
    private float[] pageArr=new float[]{0,0.5f,1.0f};
    public void OnBeginDrag(PointerEventData eventData)
    {
       // Debug.Log("Begin:");
       // Debug.Log(eventData.position);
       //获取rect的初始坐标值
        Vector2 pos = scrollRect.normalizedPosition;
        Debug.Log("Begin:"+pos);
    }
    public void OnEndDrag(PointerEventData eventData)
    {
        //Debug.Log("End:");
        //Debug.Log(eventData.position);
        //获取rect的拖动后的坐标值
        Vector2 pos = scrollRect.normalizedPosition;
        Debug.Log("End:"+pos);
        //获取rect拖动后的水平坐标值
        float posX = scrollRect.horizontalNormalizedPosition;
        int index = 0;
        //计算与特定点的偏差
        float offset = Math.Abs(pageArr[index] - posX);
        //与每一个坐标点进行比较，确定应该存在的位置
        //偏差最小的位置即为rect的位置点
        for(int i=0;i<pageArr.Length;i++)
        {
            float newOffset = Math.Abs(pageArr[i] - posX);
            if(newOffset<= offset)
            {
                index = i;
                offset = newOffset;
            }
        }
        scrollRect.horizontalNormalizedPosition = pageArr[index];
        toggleArr[index].isOn = true;
        Debug.Log("End:" + scrollRect.horizontalNormalizedPosition);
    }

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

public class DragController : MonoBehaviour, IBeginDragHandler, IEndDragHandler
{
    [SerializeField]
    private GameObject scrollRect;
    [SerializeField]
    private GameObject scrollRectSmall;

    public float distance = 600f;
    public int smoothing = 2;
    public float deltaWidth = 3840f;
    public float deltaSmallWidth = 95f;

    private List<GameObject> pages;
    private List<GameObject> smallScreens;
    private float horizontalPos = 0;
    private float horizontalPosSmall = 0;
    private List<float> postions = new List<float>();

    private bool onDrag = false;
    private float beginPos = 0; 
    private float endPos = 0;
    private int pageIndex = 0;


    public void Init(List<GameObject> pages)
    {
        this.pages = new List<GameObject>(pages);
        //this.smallScreens = smallScreens;
        pageIndex = 0;
        horizontalPos = 0;
        horizontalPosSmall = 0;
        //for (int i=0;i<pages.Count;i++)
        //{
        //    postions.Add(i);
        //}
    }

    public void OnBeginDrag(PointerEventData eventData)
    {
        onDrag = true;
        beginPos = eventData.position.x;
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        onDrag = false;
        endPos = eventData.position.x;
        float newDis = endPos - beginPos;

        if (newDis < -distance)
        {
            pageIndex++;
            if (pageIndex >= pages.Count)
            {
                pageIndex = pages.Count - 1;
            }            
        }    
        if(newDis > distance)
        {
            pageIndex--;
            if(pageIndex < 0)
            {
                pageIndex = 0;
            }
        }
        horizontalPos = -deltaWidth * pageIndex;
        //print(horizontalPos);
        horizontalPosSmall = -deltaSmallWidth * pageIndex;
        //print(horizontalPosSmall);
        pages[pageIndex].GetComponent<Toggle>().isOn = true;
        //smallScreens[pageIndex].GetComponent<Toggle>().isOn = true;
    }    

    // Use this for initialization
    void Start () {
        float scale = 3840f / Screen.width;
        deltaWidth = deltaWidth / scale;
    }

    // Update is called once per frame
    void Update () {
        if (!onDrag)
        {
            //scrollRect.GetComponent<rec = Mathf.Lerp(scrollRect.horizontalNormalizedPosition,
            //           horizontalPos, smoothing * Time.deltaTime);
            Vector2 pos = scrollRect.GetComponent<RectTransform>().position;
            float xPos = Mathf.Lerp(pos.x, horizontalPos, Time.deltaTime * smoothing);
            scrollRect.GetComponent<RectTransform>().position = new Vector2(xPos, pos.y);
            //print(xPos + " " + horizontalPos);

            //Vector2 posS = scrollRectSmall.GetComponent<RectTransform>().anchoredPosition;
            //float xPosS = Mathf.Lerp(posS.x, horizontalPosSmall, Time.deltaTime * smoothing);            
            //scrollRectSmall.GetComponent<RectTransform>().anchoredPosition = new Vector2(xPosS, posS.y);
        }
    }
}