如何根据可见视图获取CScrollView的坐标

Question

我正在使用以下例程来通过用户的鼠标操作选择矩形区域。但它目前正在基于可见视图而不是整个可滚动视图中选择区域。我想知道是否有任何方法可以在可见视图中获得（0,0）的偏移值。那就是我想在可见区域中对应于（0,0）的整个可滚动区域中找到（x，y）。

更新：找到GetScrollPosition（）。

// COpenCVTestView message handlers

void COpenCVTestView::OnLButtonDown(UINT nFlags, CPoint point)
{
    anchor = endpoint = point; 
    CClientDC dc(this); 
    dc.DrawFocusRect(&CRect(anchor.x, anchor.y, endpoint.x, endpoint.y));// very small rectangle 
    SetCapture(); 
}


void COpenCVTestView::OnLButtonUp(UINT nFlags, CPoint point)
{
    if(GetCapture() != NULL) 
    { /* banding */ 
    COpenCVTestDoc* pDoc = GetDocument();
    ASSERT_VALID(pDoc);
    if (!pDoc)
        return;
        CClientDC dc(this); 
        dc.DrawFocusRect(&CRect(anchor.x, anchor.y, endpoint.x, endpoint.y)); 
        pDoc->m_recSelection = CRect(anchor.x, anchor.y, point.x, point.y); 
        ReleaseCapture(); 
        InvalidateRect(&(pDoc->m_recSelection)); 
    } /* banding */ 
}


void COpenCVTestView::OnMouseMove(UINT nFlags, CPoint point)
{
    if(GetCapture() != NULL) 
    { /* rubber band */ 
        CClientDC dc(this); 
        dc.DrawFocusRect(&CRect(anchor.x, anchor.y, endpoint.x, endpoint.y)); 
        endpoint = point; 
        dc.DrawFocusRect(&CRect(anchor.x, anchor.y, endpoint.x, endpoint.y)); 
    } /* rubber band */ 
}