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> ()[1];
    }

    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;
    }
}