c++——chap04

/*
	HDC hdc;
	hdc = ::GetDC(m_hWnd);

	MoveToEx(hdc,m_point_down.x,m_point_down.y,NULL);
	LineTo(hdc,point.x,point.y);

	::ReleaseDC(m_hWnd,hdc);
*/

/*
	CDC *pointCDC = GetDC();
	pointCDC->MoveTo(m_point_down);
	pointCDC->LineTo(point);
	ReleaseDC(pointCDC);
*/

	/*
	CClientDC dc(this);
	//CClientDC dc(GetParent());
	dc.MoveTo(m_point_down);
	dc.LineTo(point);

	*/

	/*
	CWindowDC dc(this);
	dc.MoveTo(m_point_down);
	dc.LineTo(point);
*/
	/*
	CWindowDC dc(GetDesktopWindow());
	dc.MoveTo(m_point_down);
	dc.LineTo(point);
	*/

/*
	// 改变线的颜色
	CPen pen(PS_DOT,1,RGB(255,0,0)); // 画笔
	CClientDC dc(this);
	CPen *oldPen = dc.SelectObject(&pen);
	dc.MoveTo(m_point_down);
	dc.LineTo(point);
	dc.SelectObject(oldPen);

 

	// 画刷
	CBrush brush(RGB(0,255,0));
	CClientDC dc(this);
	dc.FillRect(CRect(m_point_down,point),&brush);


	// 位图画刷
	CBitmap bitmap;
	bitmap.LoadBitmap(IDB_BITMAP1);
	CBrush brush(&bitmap);
	CClientDC dc(this);
	dc.FillRect(CRect(m_point_down,point),&brush);
	*/

	// 透明画刷
	CClientDC dc(this);
	HGDIOBJ hgdiObj = GetStockObject(HOLLOW_BRUSH);
	CBrush *brush = CBrush::FromHandle((HBRUSH)hgdiObj);
	CBrush *oldBrush = dc.SelectObject(brush);
	dc.Rectangle(CRect(m_point_down,point));
	dc.SelectObject(oldBrush);

	CView::OnLButtonUp(nFlags, point);