（2）计算坐标点的偏移量及设置矩形新的坐标函数

void CRectGraph::SetCurRect(CPoint point)

{

    long   lX = 0,lY = 0;

    if (m_pView == NULL)       {   return;      }

        lX = point.x - m_pntPrev.x;

    lY = point.y - m_pntPrev.y;

    switch(m_lCurPos)

    {

    case SUBWIN_UP:

        {

            m_Rect.top += lY;

            break;

        }

    case SUBWIN_DOWN:

        {

            m_Rect.bottom += lY;

            break;

        }

    case SUBWIN_RIGHT:

        {

            m_Rect.right += lX;

            break;

        }

    case SUBWIN_LEFT:

        {

            m_Rect.left += lX;

            break;

        }

    case SUBWIN_WN:

        {

            m_Rect.left += lX;

            m_Rect.top += lY;

            break;

        }

    case SUBWIN_NE:

        {

            m_Rect.top += lY;

            m_Rect.right += lX;

            break;

        }

    case SUBWIN_ES:

        {

            m_Rect.right += lX;

            m_Rect.bottom += lY;

            break;

        }

    case SUBWIN_SW:

        {

            m_Rect.left += lX;

            m_Rect.bottom += lY;

            break;

        }

    case SUBWIN_IN:

        {

            m_Rect.left += lX;

            m_Rect.top += lY;

            m_Rect.right += lX;

            m_Rect.bottom += lY;

            break;

        }

    }

}