UGUI解决嵌套使用多个ScrollRect时的Drag拖动冲突问题

很简单，直接看代码：

 using UnityEngine.UI;
 using UnityEngine.EventSystems;
 using UnityEngine;

 /// <summary>
 /// 解决嵌套使用ScrollRect时的Drag冲突问题。请将该脚本放置到内层ScrollRect上(外层的ScrollRect的Drag事件会被内层的拦截)
 /// </summary>
 public class NestedScrollRect : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
 {
     /// <summary>
     /// 外层被拦截需要正常拖动的ScrollRect，可不指定，默认在父对象中找
     /// </summary>
     public ScrollRect anotherScrollRect;
     /// <summary>
     /// 当前的ScrollRect（本脚本所放置的物体上）的拖动方向默认为上下拖动，否则为左右拖动型
     /// </summary>
     public bool thisIsUpAndDown = true;

     private ScrollRect thisScrollRect;

     void Awake ()
     {
         thisScrollRect = GetComponent<ScrollRect> ();
         if (anotherScrollRect == null)
             anotherScrollRect = GetComponentsInParent<ScrollRect> ()[];
     }

     public void OnBeginDrag (PointerEventData eventData)
     {
         anotherScrollRect.OnBeginDrag (eventData);
     }

     public void OnDrag (PointerEventData eventData)
     {
         anotherScrollRect.OnDrag (eventData);
         float angle = Vector2.Angle (eventData.delta, Vector2.up);
         //判断拖动方向，防止水平与垂直方向同时响应导致的拖动时整个界面都会动
         if (angle > 45f && angle < 135f)
         {
             thisScrollRect.enabled = !thisIsUpAndDown;
             anotherScrollRect.enabled = thisIsUpAndDown;
         }
         else
         {
             anotherScrollRect.enabled = !thisIsUpAndDown;
             thisScrollRect.enabled = thisIsUpAndDown;
         }
     }

     public void OnEndDrag (PointerEventData eventData)
     {
         anotherScrollRect.OnEndDrag (eventData);
         anotherScrollRect.enabled = true;
         thisScrollRect.enabled = true;
     }
 }