UGUI 实现拖拽功能的 简单代码

重写方法

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
namespace Com.Company.Mission
{
    public class EventTriggerListener : MonoBehaviour, IPointerClickHandler, IPointerDownHandler, IPointerEnterHandler,
        IPointerExitHandler, IPointerUpHandler
    {
        public delegate void VoidDelegate1(GameObject go, PointerEventData eventData);

        public event VoidDelegate1 OnClick;
        public event VoidDelegate1 OnDown;
        public event VoidDelegate1 OnEnter;
        public event VoidDelegate1 OnExit;
        public event VoidDelegate1 OnUp;

        static public EventTriggerListener Get(GameObject go)
        {
            EventTriggerListener listener = go.GetComponent<EventTriggerListener>();
            if (listener == null) listener = go.AddComponent<EventTriggerListener>();
            return listener;
        }

        public void OnPointerClick(PointerEventData eventData)
        {
            if (OnClick != null) OnClick(gameObject, eventData);
        }

        public void OnPointerDown(PointerEventData eventData)
        {
            if (OnDown != null) OnDown(gameObject, eventData);
        }

        public void OnPointerEnter(PointerEventData eventData)
        {
            if (OnEnter != null) OnEnter(gameObject, eventData);
        }

        public void OnPointerExit(PointerEventData eventData)
        {
            if (OnExit != null) OnExit(gameObject, eventData);
        }

        public void OnPointerUp(PointerEventData eventData)
        {
            if (OnUp != null) OnUp(gameObject, eventData);
        }

    }
}

挂在需要拖拽的地方

using System.Collections.Generic;
using Com.Company.ConfigData.MissionArea;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace Com.Company.Mission
{
    [RequireComponent(typeof(Image))]
    public class DragMe : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
    {
        private MissionAreaData data;

        public MissionAreaData Data { get; set; }
        public bool dragOnSurfaces = true;

        private Dictionary<int, GameObject> m_DraggingIcons = new Dictionary<int, GameObject>();
        private Dictionary<int, RectTransform> m_DraggingPlanes = new Dictionary<int, RectTransform>();

        public void OnBeginDrag(PointerEventData eventData)
        {
            var canvas = FindInParents<Canvas>(gameObject);
            if (canvas == null)
                return;
            
            m_DraggingIcons[eventData.pointerId] = new GameObject("icon");
            m_DraggingIcons[eventData.pointerId].transform.SetParent(canvas.transform, false);
            m_DraggingIcons[eventData.pointerId].transform.SetAsLastSibling();


            var image = m_DraggingIcons[eventData.pointerId].AddComponent<Image>();
            var group = m_DraggingIcons[eventData.pointerId].AddComponent<CanvasGroup>();
            group.blocksRaycasts = false;

            image.sprite = GetComponent<Image>().sprite;
            image.SetNativeSize();
            image.GetComponent<RectTransform>().sizeDelta = new Vector2(200, 200);
            if (dragOnSurfaces)
                m_DraggingPlanes[eventData.pointerId] = transform as RectTransform;
            else
                m_DraggingPlanes[eventData.pointerId] = canvas.transform as RectTransform;

            SetDraggedPosition(eventData);
        }

        public void OnDrag(PointerEventData eventData)
        {
            if (m_DraggingIcons[eventData.pointerId] != null)
                SetDraggedPosition(eventData);
        }

        private void SetDraggedPosition(PointerEventData eventData)
        {
            if (dragOnSurfaces && eventData.pointerEnter != null &&
                eventData.pointerEnter.transform as RectTransform != null)
                m_DraggingPlanes[eventData.pointerId] = eventData.pointerEnter.transform as RectTransform;

            var rt = m_DraggingIcons[eventData.pointerId].GetComponent<RectTransform>();
            Vector3 globalMousePos;
            if (RectTransformUtility.ScreenPointToWorldPointInRectangle(m_DraggingPlanes[eventData.pointerId],
                eventData.position, eventData.pressEventCamera, out globalMousePos))
            {
                rt.position = globalMousePos;
                rt.rotation = m_DraggingPlanes[eventData.pointerId].rotation;
            }
        }

        public void OnEndDrag(PointerEventData eventData)
        {
            if (m_DraggingIcons[eventData.pointerId] != null)
                Destroy(m_DraggingIcons[eventData.pointerId]);

            m_DraggingIcons[eventData.pointerId] = null;
        }

        static public T FindInParents<T>(GameObject go) where T : Component
        {
            if (go == null) return null;
            var comp = go.GetComponent<T>();

            if (comp != null)
                return comp;

            var t = go.transform.parent;
            while (t != null && comp == null)
            {
                comp = t.gameObject.GetComponent<T>();
                t = t.parent;
            }

            return comp;
        }
    }
}

挂在拖在的地方

using System.Reflection;
using Com.Company.ConfigData.MissionArea;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace Com.Company.Mission
{
    public class DropMe : MonoBehaviour, IDropHandler, IPointerEnterHandler, IPointerExitHandler
    {
        private MissionAreaData data;

        public MissionAreaData Data { get; set; }
        
        public Image containerImage;
        public Image receivingImage;
        private Color normalColor;
        public Color highlightColor = Color.yellow;

        public void OnEnable()
        {
            receivingImage = this.GetComponent<Image>();
            if (containerImage != null)
                normalColor = containerImage.color;
        }

        public void OnDrop(PointerEventData data)
        {
            containerImage = data.pointerDrag.GetComponent<Image>();
            containerImage.raycastTarget = false;
            containerImage.color = normalColor;
            Data = containerImage.GetComponent<DragMe>().Data;

            if (receivingImage == null)
                return;

            Sprite dropSprite = GetDropSprite(data);
            if (dropSprite != null)
                receivingImage.overrideSprite = dropSprite;
        }

        public void OnPointerEnter(PointerEventData data)
        {
            if (containerImage == null)
                return;

            // Sprite dropSprite = GetDropSprite (data);
            // if (dropSprite != null)
            //containerImage.color = highlightColor;
        }

        public void OnPointerExit(PointerEventData data)
        {
            if (containerImage == null)
                return;

            containerImage.color = normalColor;
        }

        private Sprite GetDropSprite(PointerEventData data)
        {
            var originalObj = data.pointerDrag;
            if (originalObj == null)
                return null;

            var dragMe = originalObj.GetComponent<DragMe>();
            if (dragMe == null)
                return null;

            var srcImage = originalObj.GetComponent<Image>();
            if (srcImage == null)
                return null;

            return srcImage.sprite;
        }
    }
}