[팁] 메모리 DC

class CMemDC : public CDC {
private:
CBitmap* m_bitmap;
CBitmap* m_oldBitmap;
CDC* m_pDC;
CRect m_rcBounds;
public:
CMemDC(CDC* pDC, const CRect& rcBounds) : CDC()
{
CreateCompatibleDC(pDC);
m_bitmap = new CBitmap;
m_bitmap->CreateCompatibleBitmap(pDC, rcBounds.Width(), rcBounds.Height());
m_oldBitmap = SelectObject(m_bitmap);
m_pDC = pDC;
m_rcBounds = rcBounds;
}
~CMemDC()
{
m_pDC->BitBlt(m_rcBounds.left, m_rcBounds.top, m_rcBounds.Width(), m_rcBounds.Height(),
this, m_rcBounds.left, m_rcBounds.top, SRCCOPY);
SelectObject(m_oldBitmap);
if (m_bitmap != NULL) delete m_bitmap;
}
CMemDC* operator->() {
return this;
}
};


OnDraw(){
CRect rect;
GetClientRect(&rect);
CMemDC dc(pDC, rect);
dc->FillRect(rect, CBrush::FromHandle((HBRUSH)GetStockObject(WHITE_BRUSH)));

// TODO: add draw code for native data here
}