如何在指定矩形中旋轉顯示文字

徐景周

///////////////////////////////////////////////////////
//說明：
//  在矩形框中旋轉方式顯示文字，jingzhou xu
//參數：    
//  pDC:      DC指針
//  str:      顯示文字
//  rect:      顯示范圍
//  angle:      旋轉角度
//   nOptions:   ExtTextOut()中相應設置<ETO_CLIPPED 和 ETO_OPAQUE>
///////////////////////////////////////////////////////
void DrawRotatedText(CDC* pDC, const CString str, CRect rect,
                     double angle, UINT nOptions)
{
   //按比例轉換角度值
   double pi = 3.141592654;
   double radian = pi * 2 / 360 * angle;

   //獲取顯示文字中心點
   CSize TextSize = pDC->GetTextExtent(str);
   CPoint center;
   center.x = TextSize.cx / 2;
   center.y = TextSize.cy / 2;

   //計算顯示文字新的中心點
   CPoint rcenter;
   rcenter.x = long(cos(radian) * center.x - sin(radian) * center.y);
   rcenter.y = long(sin(radian) * center.x + cos(radian) * center.y);

   //繪制文字
   pDC->SetTextAlign(TA_BASELINE);
   pDC->SetBkMode(TRANSPARENT);
   pDC->ExtTextOut(rect.left + rect.Width() / 2 - rcenter.x,
                   rect.top + rect.Height() / 2 + rcenter.y,
                   nOptions, rect, str, NULL);
}

用法：
   DrawRotatedText (pDC,”VC知識庫”,CRect(100,100,300,300),15, ETO_CLIPPED);

原文轉自：http://www.kjueaiud.com