MFC繪制不同背景顔色而顯示不同前景色的虛線矩形

效果預覽圖：

以下是實作代碼：

void CControlButton::DrawVirtualFrame(CDC * pDC, CRect rectScreen)
{
	CRect rectVirtual(rectScreen.left + m_usLeftX, rectScreen.top + m_usLeftY, rectScreen.left + m_usRightX, rectScreen.top + m_usRightY);

  	DWORD style[4] = {1, 1, 1, 1};//繪制不同背景顔色而顯示不同前景色的虛線矩形
  	LOGBRUSH logBrush;
  	logBrush.lbColor = RGB(0, 0, 0);
  	logBrush.lbStyle = BS_SOLID;
  	CPen pen(PS_USERSTYLE, 1, &logBrush, 4, style);
  	CBrush * pBrush = CBrush::FromHandle((HBRUSH)GetStockObject(NULL_BRUSH));//背景透明效果
  	CBrush * pOldBrush = pDC->SelectObject(pBrush);
  	CPen * pOldPen = pDC->SelectObject(&pen);
  	int nOldMode = pDC->SetROP2(R2_NOT);//像素是螢幕顔色的反向操作。
  	pDC->Rectangle(rectVirtual);
  	pDC->SelectObject(pOldBrush);
  	pDC->SelectObject(pOldPen);
  	pDC->SetROP2(nOldMode);
}