在Unity3D中拖放ScrollRect(ScrollView)

ATH*_*boy 1 drag-and-drop eventtrigger scrollrect scrollview unity-game-engine

我想在滚动视图的内容上实现拖放。

问题是,当您尝试在滚动视图中拖动项目时,无法滚动视图。

首先,我尝试通过IDragHandler,IBeginDragHandler,IEndDragHandle和IDropHandler接口实现拖放。乍一看,它工作得很好,但问题是您无法滚动ScrollRect。

我认为问题是由于重载造成的,当我使用事件触发器与拖动一样像rect rect时,父触发器无法正常工作。

因此,在那之后,我自己思考了一下,并通过IPointerDown,IPointerUp接口和在ScrollRect中保留可拖动UI的特定时间来实现它,如果您没有在特定时间保持它,则滚动工作会很好。

但是问题是通过启用在保持时间结束时在OnDrag,OnBeginDrag和OnEndDrag函数之前编写的DragHandler脚本不起作用。

首先我想知道有什么方法可以调用这些函数吗?

其次,有什么方法可以在不使用拖动界面的情况下实现拖放UI?

DragHandler:

using System;
using UnityEngine;
using UnityEngine.EventSystems;

public class DragHandler : MonoBehaviour, IDragHandler, IBeginDragHandler, IEndDragHandler
{
    public static GameObject itemBeingDragged;

    private Vector3 startPos;

    private Transform startParent;

    DragHandler dragHandler;

    public void Awake()
    {
        dragHandler = GetComponent<DragHandler>();
    }

    public void OnBeginDrag(PointerEventData eventData)
    {
        Debug.Log("Begin");
        itemBeingDragged = gameObject;
        startPos = transform.position;
        startParent = transform.parent;
    }

    public void OnDrag(PointerEventData eventData)
    {
        Debug.Log("Drag");
        transform.position = Input.mousePosition;
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        Debug.Log("End");
        itemBeingDragged = null;
        if (transform.parent == startParent)
        {
            dragHandler.enabled = false;
            transform.SetParent(startParent);
            transform.position = startPos;
        }
    }
}
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ScrollRectController:

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

public class ScrollRectController : MonoBehaviour, IPointerDownHandler, IPointerUpHandler
{
    public float holdTime;
    public float maxVelocity;

    private Transform scrollRectParent;

    private DragHandler dragHandler;

    private ScrollRect scrollRect;

    private float timer;

    private bool isHolding;

    void Awake()
    {
        scrollRectParent = GameObject.FindGameObjectWithTag("rec_dlg").transform;
        dragHandler = GetComponent<DragHandler>();
        dragHandler.enabled = false;
    }

    // Use this for initialization
    void Start()
    {
        timer = holdTime;
    }

    // Update is called once per frame
    void Update()
    {

    }

    public void OnPointerDown(PointerEventData eventData)
    {
        Debug.Log("Down");
        scrollRect = scrollRectParent.GetComponent<ScrollRect>();
        isHolding = true;
        StartCoroutine(Holding());
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        Debug.Log("Up");
        isHolding = false;
    }

    IEnumerator Holding()
    {
        while (timer > 0)
        {
            //if (scrollRect.velocity.x >= maxVelocity)
            //{
            //    isHolding = false;
            //}

            if (!isHolding)
            {
                timer = holdTime;
                yield break;
            }

            timer -= Time.deltaTime;
            Debug.Log(timer);
            yield return null;
        }

        dragHandler.enabled = true;
        //dragHandler.OnBeginDrag();
    }
}
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广告位:

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

public class Slot : MonoBehaviour, IDropHandler
{
    public void OnDrop(PointerEventData eventData)
    {
        DragHandler.itemBeingDragged.transform.SetParent(transform);
    }
}
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小智 8

此问题最简单的解决方案实际上是,如果用户没有使用ExecuteEvents.Execute按下足够长的时间,则手动调用ScrollRect 的事件。该解决方案的附加代码量最少。

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

public class DragAndDropHandler : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IPointerExitHandler, IDragHandler, IBeginDragHandler, IEndDragHandler
{
    // Don't forget to set this to TRUE or expose it to the Inspector else it will always be false and the script will not work
    public bool Draggable { get; set; }

    private bool draggingSlot;

    [SerializeField] private ScrollRect scrollRect;

    public void OnPointerDown(PointerEventData eventData)
    {
        if (!Draggable)
        {
            return;
        }

        StartCoroutine(StartTimer());
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        StopAllCoroutines();
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        StopAllCoroutines();
    }

    private IEnumerator StartTimer()
    {
        yield return new WaitForSeconds(0.5f);
        draggingSlot = true;
    }

    public void OnBeginDrag(PointerEventData eventData)
    {
        ExecuteEvents.Execute(scrollRect.gameObject, eventData, ExecuteEvents.beginDragHandler);
    }

    public void OnDrag(PointerEventData eventData)
    {
        if (draggingSlot)
        {
            //DO YOUR DRAGGING HERE
        } else
        {
            //OR DO THE SCROLLRECT'S
            ExecuteEvents.Execute(scrollRect.gameObject, eventData, ExecuteEvents.dragHandler);
        }
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        ExecuteEvents.Execute(scrollRect.gameObject, eventData, ExecuteEvents.endDragHandler);
        if (draggingSlot)
        {
            //END YOUR DRAGGING HERE
            draggingSlot = false;
        }
    }
}
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ATH*_*boy 6

回答:

我编写了一些无需使用DragHandler接口即可处理scrollRect(scrollView)中的拖放的代码。

DragHandler:

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

public class DragHandler : MonoBehaviour, IPointerExitHandler
{
    public static GameObject itemBeingDragged;

    public static bool isCustomerDragged;

    public Transform customerScrollRect;
    public Transform dragParent;

    public float holdTime;
    public float maxScrollVelocityInDrag;

    private Transform startParent;

    private ScrollRect scrollRect;

    private float timer;

    private bool isHolding;
    private bool canDrag;
    private bool isPointerOverGameObject;

    private CanvasGroup canvasGroup;

    private Vector3 startPos;

    public Transform StartParent
    {
        get { return startParent; }
    }

    public Vector3 StartPos
    {
        get { return startPos; }
    }

    void Awake()
    {
        canvasGroup = GetComponent<CanvasGroup>();
    }

    // Use this for initialization
    void Start()
    {
        timer = holdTime;
    }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            if (EventSystem.current.currentSelectedGameObject == gameObject)
            {
                //Debug.Log("Mouse Button Down");
                scrollRect = customerScrollRect.GetComponent<ScrollRect>();
                isPointerOverGameObject = true;
                isHolding = true;
                StartCoroutine(Holding());
            }
        }

        if (Input.GetMouseButtonUp(0))
        {
            if (EventSystem.current.currentSelectedGameObject == gameObject)
            {
                //Debug.Log("Mouse Button Up");
                isHolding = false;

                if (canDrag)
                {
                    itemBeingDragged = null;
                    isCustomerDragged = false;
                    if (transform.parent == dragParent)
                    {
                        canvasGroup.blocksRaycasts = true;
                        transform.SetParent(startParent);
                        transform.localPosition = startPos;
                    }
                    canDrag = false;
                    timer = holdTime;
                }
            }
        }

        if (Input.GetMouseButton(0))
        {
            if (EventSystem.current.currentSelectedGameObject == gameObject)
            {
                if (canDrag)
                {
                    //Debug.Log("Mouse Button");
                    transform.position = Input.mousePosition;
                }
                else
                {
                    if (!isPointerOverGameObject)
                    {
                        isHolding = false;
                    }
                }
            }
        }
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        isPointerOverGameObject = false;
    }

    IEnumerator Holding()
    {
        while (timer > 0)
        {
            if (scrollRect.velocity.x >= maxScrollVelocityInDrag)
            {
                isHolding = false;
            }

            if (!isHolding)
            {
                timer = holdTime;
                yield break;
            }

            timer -= Time.deltaTime;
            //Debug.Log("Time : " + timer);
            yield return null;
        }

        isCustomerDragged = true;
        itemBeingDragged = gameObject;
        startPos = transform.localPosition;
        startParent = transform.parent;
        canDrag = true;
        canvasGroup.blocksRaycasts = false;
        transform.SetParent(dragParent);
    }

    public void Reset()
    {
        isHolding = false;
        canDrag = false;
        isPointerOverGameObject = false;
    }
}
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这段代码的一些解释:

  1. 您的可拖动UI元素需要一些棘手的选项,对我来说,我使用的是按钮。
  2. 您需要将此脚本附加到可拖动项。
  3. 另外,您需要添加画布组组件。
  4. customerScrollRect是您的商品的ScrollRect父级。
  5. dragParent可以是一个空的GameObject,它由于使用视口的遮罩而被使用。

广告位:

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

public class Slot : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler
{
    bool isEntered;

    public void OnPointerEnter(PointerEventData eventData)
    {
        isEntered = true;
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        isEntered = false;
    }

    void Update()
    {
        if (Input.GetMouseButtonUp(0))
        {
            if (isEntered)
            {
                if (DragHandler.itemBeingDragged)
                {
                    GameObject draggedItem = DragHandler.itemBeingDragged;
                    DragHandler dragHandler = draggedItem.GetComponent<DragHandler>();
                    Vector3 childPos = draggedItem.transform.position;
                    //Debug.Log("On Pointer Enter");
                    draggedItem.transform.SetParent(dragHandler.StartParent);
                    draggedItem.transform.localPosition = dragHandler.StartPos;
                    draggedItem.transform.parent.SetParent(transform);
                    draggedItem.transform.parent.position = childPos;
                    isEntered = false;
                }
            }
        }
    }
}
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此脚本的一些解释:

1.将脚本附加到放置的项目。