mfc- Picture control顯示圖片

 

一、放一個Pictrue控制項屬性Type設為Owner Draw
調整大小
二、加一個按鈕控制項用於處理圖片載入，添加事件

三、按鈕單擊事件
 char* m_JPGBuf ;
 int m_JPGLen;//標頭檔中定義

void Cbmlb::OnBnClickedBtnUplogpic()
{
 CString PicPath;
 CFileDialog fdlg(TRUE,NULL,NULL,OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT,"JPEG影像檔|*.jpg|BMP影像檔|*.bmp||");
 if (fdlg.DoModal() == IDOK)
 { 
  PicPath = fdlg.GetPathName();
  CFile file;
  if(file.Open(PicPath,CFile::modeRead) && ((m_JPGLen = file.GetLength()) != -1))
  {
   m_JPGBuf = (char *)malloc(m_JPGLen);
   file.Read(m_JPGBuf, m_JPGLen);
   file.Close();
  }

  DisplayJPG(m_JPGBuf,m_JPGLen);
 }
 ((CStatic*)GetDlgItem(IDC_EDIT_PicPath))->SetWindowText(PicPath);//編輯框可以顯示圖片路經
｝
四、編輯圖片處理方法

BOOL Cbmlb::DisplayJPG(char* JPGBuf ,int JPGLen)
{
 m_JPGBuf = JPGBuf;
 m_JPGLen = JPGLen;
 IStream *pStm;
 LPVOID pvData;
 HGLOBAL hGlobal;
 CRect   m_DisplayRect,m_winRect;
 CDC* m_pDisplayCDC;
 m_pDisplayCDC = m_PersonPicBtn.GetDC();
 m_PersonPicBtn.GetClientRect(&m_DisplayRect);//擷取畫單張圖的RECT

 double m_HORZRES = (double)m_pDisplayCDC->GetDeviceCaps(HORZRES);
 double m_VERTSIZE = (double)m_pDisplayCDC->GetDeviceCaps(VERTSIZE);

 if(JPGBuf == NULL)
 {
  CBrush br(RGB(0,0,0));
  m_pDisplayCDC->FillRect(&m_DisplayRect, &br);
  return FALSE;
 }

 char *pJPGBuf = JPGBuf;
 int iJPGLen = JPGLen;
 hGlobal = GlobalAlloc(GMEM_MOVEABLE, iJPGLen);
 pvData = NULL;
 if(hGlobal != NULL)
 {
  pvData = GlobalLock(hGlobal);
  if(pvData != NULL)
  {
   memcpy(pvData,pJPGBuf,iJPGLen);
   GlobalUnlock(hGlobal);
   CreateStreamOnHGlobal(hGlobal, TRUE, &pStm);
  }
 }

 //開啟檔案結束
 //顯示JPEG和GIF格式的圖片，GIF只能顯示一幀，還不能顯示動畫，
 //要顯示動畫GIF請使用ACTIVE控//件。
 IPicture *pPic;     //load image from file stream
 if(SUCCEEDED(OleLoadPicture(pStm,iJPGLen,TRUE,IID_IPicture,(LPVOID*)&pPic)))
 {
  OLE_XSIZE_HIMETRIC hmWidth;
  OLE_YSIZE_HIMETRIC hmHeight;
  pPic->get_Width(&hmWidth);
  pPic->get_Height(&hmHeight);      
  double fX,fY;
  //get image height and width       
  fX = m_HORZRES*(double)hmWidth/(m_HORZRES*100.0);
  fY = m_VERTSIZE*(double)hmHeight/(m_VERTSIZE*100.0);
  //use render function display image 
  if(FAILED(pPic->Render(*m_pDisplayCDC,0,0,m_DisplayRect.Width(),m_DisplayRect.Height(),0,hmHeight,hmWidth,-hmHeight,NULL)))
  {           
   pPic->Release();
   pStm->Release();
   if(hGlobal != NULL)
    GlobalFree(hGlobal);
   ReleaseDC(m_pDisplayCDC);
   return FALSE;     
  }
  pPic->Release(); 
  pStm->Release();
 }
 else
 {
  pStm->Release();
  if(hGlobal != NULL)
   GlobalFree(hGlobal);
  ReleaseDC(m_pDisplayCDC);
  return FALSE;
 }
 if(hGlobal != NULL)
 {
  GlobalFree(hGlobal);
 }

 ReleaseDC(m_pDisplayCDC);

 return TRUE; 
}
五、加ONPAIN方法
void Cbmlb::OnPaint()
{
 CPaintDC dc(this); // device context for painting
 // TODO: 在此處添加訊息處理常式代碼
 // 不為繪圖訊息調用 CDialog::OnPaint()
 DisplayJPG(m_JPGBuf,m_JPGLen);

}

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