using UnityEngine;using UnityEngine.EventSystems;using UnityEngine.UI;[RequireComponent(typeof(Image))]public class DragMe : MonoBehaviour, IBeginDragHandler, IDragHandler,IEndDragHandler{    public bool dragOnSurfaces = true;    public GameObject m_DraggingIcon;    private RectTransform m_DraggingPlane;    public void OnBeginDrag(PointerEventData eventData)    {        var canvas = FindInParents
     
      (gameObject);        if (canvas == null)            return;        // We have clicked something that can be dragged.        // What we want to do is create an icon for this.        m_DraggingIcon = new GameObject("icon");        m_DraggingIcon.transform.SetParent(canvas.transform, false);        m_DraggingIcon.transform.SetAsLastSibling();        var image = m_DraggingIcon.AddComponent
      ();        // The icon will be under the cursor.        // We want it to be ignored by the event system.        CanvasGroup group = m_DraggingIcon.AddComponent
      
       ();        group.blocksRaycasts = false;        image.sprite = GetComponent
       ().sprite;        image.SetNativeSize();        if (dragOnSurfaces)        {            m_DraggingPlane = transform as RectTransform;        }        else        {            m_DraggingPlane = canvas.transform as RectTransform;        }        SetDraggedPosition(eventData);    }    public void OnDrag(PointerEventData data)    {        if (m_DraggingIcon != null)        {            SetDraggedPosition(data);        }        transform.position = m_DraggingIcon.transform.position;        m_DraggingIcon.SetActive(false);    }    private void SetDraggedPosition(PointerEventData data)    {        if (dragOnSurfaces && data.pointerEnter != null && data.pointerEnter.transform as RectTransform != null)        {            m_DraggingPlane = data.pointerEnter.transform as RectTransform;        }        var rt = m_DraggingIcon.GetComponent
       
        ();        Vector3 globalMousePos;        if (RectTransformUtility.ScreenPointToWorldPointInRectangle(m_DraggingPlane, data.position, data.pressEventCamera, out globalMousePos))        {            rt.position = globalMousePos;            rt.rotation = m_DraggingPlane.rotation;        }    }    public void OnEndDrag(PointerEventData eventData)    {        if (m_DraggingIcon != null)            Destroy(m_DraggingIcon);        Debug.Log("万用表的位置"+transform.position);    }    static public T FindInParents
        
         (GameObject go) where T : Component    {        if (go == null)        {            return null;        }        var comp = go.GetComponent
         
          ();        if (comp != null)        {            return comp;        }        Transform t = go.transform.parent;        while (t != null && comp == null)        {            comp = t.gameObject.GetComponent
          
           (); t = t.parent; } return comp; } }