嵌套列表拖拽事件冲突问题

Posted 2021-12-08 qinshuaijun

今天项目中遇到这类需求，我的项目是循环列表与列表的冲突，导致事件被拦截，苦思两天终于搞定，上代码

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 UINestedScrollRect : 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 m_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 m_ThisIsUpAndDown = true;
    private LoopScrollRect m_ThisScrollRect;

    void Awake()
    {
        m_ThisScrollRect = GetComponent<LoopScrollRect>();
        if (m_AnotherScrollRect == null)
            m_AnotherScrollRect = GetComponentsInParent<ScrollRect>()[0];
    }

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

    public void OnDrag(PointerEventData eventData)
    {
        m_AnotherScrollRect.OnDrag(eventData);
        float angle = Vector2.Angle(eventData.delta, Vector2.left);

        //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)
        {
            m_ThisScrollRect.enabled = !m_ThisIsUpAndDown;
            m_AnotherScrollRect.enabled = m_ThisIsUpAndDown;
        }
        else
        {
            m_AnotherScrollRect.enabled = !m_ThisIsUpAndDown;
            m_ThisScrollRect.enabled = m_ThisIsUpAndDown;
        }
    }
    public void OnEndDrag(PointerEventData eventData)
    {
        m_AnotherScrollRect.OnEndDrag(eventData);
        m_AnotherScrollRect.enabled = true;
        m_ThisScrollRect.enabled = true;
    }
}

完美解决事件拦截问题，可以根据自己的需求改对应的参数