MFC绘图

看孙鑫视频上第四章写的

主要代码：

void CDrawView::OnLButtonDown(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    //MessageBox("down");
    m_ptOrigin = c_ptOld = point;
    m_bDraw = TRUE;
    CView::OnLButtonDown(nFlags, point);
}


void CDrawView::OnLButtonUp(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    //MessageBox("up");
    /*
    HDC hdc = ::GetDC(m_hWnd);
    MoveToEx(hdc, m_ptOrigin.x, m_ptOrigin.y, NULL);
    LineTo(hdc, point.x, point.y);
    ::ReleaseDC(m_hWnd, hdc);
    */
    /*
    CDC *pDC = GetDC();
    pDC->MoveTo(m_ptOrigin);
    pDC->LineTo(point);
    ReleaseDC(pDC);
    */
    /*
    CClientDC dc(this);
    //CClientDC dc(GetParent());
    dc.MoveTo(m_ptOrigin);
    dc.LineTo(point);
    */
    /*
    //CWindowDC dc(this);
    //CWindowDC dc(GetParent());
    CWindowDC dc(GetDesktopWindow());
    dc.MoveTo(m_ptOrigin);
    dc.LineTo(point);
    */
    /*
    //CPen pen(PS_SOLID, 90, RGB(65, 88, 65));
    //CPen pen(PS_DASH, 1, RGB(65, 88, 65));
    CPen pen(PS_DOT, 1, RGB(65, 88, 65));
    CClientDC dc(this);
    CPen * pOldPen = dc.SelectObject(&pen);
    dc.MoveTo(m_ptOrigin);
    dc.LineTo(point);
    dc.SelectObject(pOldPen);
    */
    //CBrush brush(RGB(23, 22, 67));
    
    //CBitmap bitmap;
    //bitmap.LoadBitmap(IDB_BITMAP1);
    //CBrush brush(&bitmap);
    //CClientDC dc(this);
    //dc.FillRect(CRect(m_ptOrigin, point), &brush);
    
    /*
    CClientDC dc(this);
    CBrush *pBrush = CBrush::FromHandle((HBRUSH)GetStockObject(NULL_BRUSH));
    CBrush *pOldBrush = dc.SelectObject(pBrush);
    dc.Rectangle(CRect(m_ptOrigin, point));
    dc.SelectObject(pOldBrush);
    */

    m_bDraw = FALSE;
    CView::OnLButtonUp(nFlags, point);
}


void CDrawView::OnMouseMove(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    CClientDC dc(this);
    CPen pen(PS_SOLID, 0, RGB(65, 88, 65));
    CPen *pOldPen = dc.SelectObject(&pen);
    if(m_bDraw == TRUE){
        dc.SetROP2(R2_BLACK);
        dc.MoveTo(m_ptOrigin);
        //dc.LineTo(point);
        dc.LineTo(c_ptOld);
        //dc.MoveTo(m_ptOrigin);
        dc.MoveTo(c_ptOld);
        dc.LineTo(point);
        //m_ptOrigin = point;
        c_ptOld = point;
    }
    dc.SelectObject(pOldPen);
    CView::OnMouseMove(nFlags, point);
}

讲了好几种方法，主要用的还是CClientDC这种的吧