unity3d：物体点击与拖动互不影响

private bool bInTouch = false;
    private float ClickAfter = 0.0f;
    GameObject m_curClickBox;
    private Vector3 mousePosLast = Vector3.zero;
    private bool Dragged = false;

    private bool bTemporarySelect = false;

public void Update()
    {
        
        //有按钮一直按下，在PC端是鼠标左键一直按下。。移动端可代表一直在滑动
        if (Input.GetMouseButton(0))
        {
            //点击到UI上
            if (Application.isMobilePlatform && Input.touchCount > 0)
            {
                if (EventSystem.current.IsPointerOverGameObject(Input.GetTouch(0).fingerId))
                    return;
            }
            else if (EventSystem.current.IsPointerOverGameObject())
            {
                return;
            }

            //未点在UI上，
            //之前没按下
            if (bInTouch == false)
            {

                bInTouch = true;//当前点击了一个建筑
                ClickAfter = 0.0f;
                mousePosLast = Input.mousePosition;
                bTemporarySelect = false;
                Dragged = false;
            }
            else //之前按下了
            {
                //与上次点击距离超过阈值为滑动
                if (Vector3.Distance(Input.mousePosition, mousePosLast) > 0.01f)
                {
                    if (!Dragged)
                    {
                        Dragged = true;
                    }
                }
                else //按下，且一直长按超过阈值 为点击
                {
                    if (!Dragged)
                    {
                        ClickAfter += Time.deltaTime;
                        if (!bTemporarySelect && (ClickAfter > 0.5f))
                        {
                            bTemporarySelect = true;
                            //Debug.Log ("Update2 buildingSelected:"+((buildingSelected != null) ? buildingSelected.name : "none"));
                            //按下到松手且不移动，判定为点击状态
                            PickOneBox();
                        }
                    }
                }
            }
        }
        else //触摸抬起或者按下，实际处理抬起事件
        {
            if (bInTouch)
            {
                bInTouch = false;

                if (Dragged)
                {
                    //在持续期间判断为拖动，执行拖动逻辑
                }
                else//执行点击
                {
                    if (bTemporarySelect) //长按
                    {
                    }
                    else
                    {
                        PickOneBox();
                    }
                }
            }
        }
    }

void PickOneBox()
    {
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        RaycastHit hit;
        if (Physics.Raycast(ray, out hit))
        {
            if (hit.collider.gameObject.tag == "HtBox")
            {
                hit.collider.gameObject.GetComponent<BoxCtrl>().OnPick();
              
            }   
        }
    }