m_Startpt = point; //确定滚动区域 CRect rcScroll = m_ClientRect; rcScroll.left += m_ThumbWidth; rcScroll.right-= m_ThumbWidth; DWORD wparam; SetCapture(); if (m_ThumbRect.PtInRect(point)) { m_ButtonDown = TRUE; } else if (rcScroll.PtInRect(point)) //单击滚动区域 { CPoint centerPt = m_