伸缩位图

StretchBlt函数 

void CStretchBltView::OnDraw(CDC* pDC)
{
	CStretchBltDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
	// TODO: add draw code for native data here
	CBitmap bitmap;                                  //声明CBitmap对象
	CDC dc;                                          //CDC对象
	bitmap.LoadBitmap(IDB_BITMAP1);                  //加载资源
	dc.CreateCompatibleDC(pDC);                      //创建和pDC一样的内存设备环境
	dc.SelectObject(&bitmap);                        //将位图选入内存环境中
	pDC->BitBlt(0,0,600,800,&dc,0,0,SRCCOPY);        //显示位图

	//缩小一半显示
	pDC->StretchBlt(650,0,600/2,800/2,&dc,160,160,600,800,SRCCOPY);
}