vc显示jpg,gif图像简单方法

VC没有直接显示JPG图片的方法，在网上找了个比较简单的列子自己改了下，还挺好用，下面一个函数就行了

 

ShowJpgGif(CDC* pDC,CString strPath, int x, int y)
{
      IStream *pStm;
      CFileStatus fstatus;
      CFile file;
      LONG cb;
      if (file.Open(strPath,CFile::modeRead)&&file.GetStatus(strPath,fstatus)&&((cb = fstatus.m_size) != -1))
      {
            HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, cb);
            LPVOID pvData = NULL;
            if (hGlobal != NULL)
            {
                  pvData = GlobalLock(hGlobal);
                  if (pvData != NULL)
                  {
                        file.Read(pvData, cb);
                        GlobalUnlock(hGlobal);
                        CreateStreamOnHGlobal(hGlobal, TRUE, &pStm);
                  }
            }
      }
      else
            return false;
      //显示JPEG和GIF格式的图片，GIF只能显示一帧，还不能显示动画，
      //要显示动画GIF请使用ACTIVE控//件。
      IPicture *pPic;
      //load image from file stream
      if(SUCCEEDED(OleLoadPicture(pStm,fstatus.m_size,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 = (double)pDC->GetDeviceCaps(HORZRES)*(double)hmWidth/((double)pDC->GetDeviceCaps(HORZSIZE)*100.0);
            fY = (double)pDC->GetDeviceCaps(VERTRES)*(double)hmHeight/((double)pDC->GetDeviceCaps(VERTSIZE)*100.0);
            //use render function display image
            if(FAILED(pPic->Render(*pDC,x,y,(DWORD)fX,(DWORD)fY,0,hmHeight,hmWidth,-hmHeight,NULL)))
            {
                  pPic->Release();
                  return false;
            }
            pPic->Release();
      }
      else
            return false;
      return true;
}

ShowJpgGif(CDC* pDC,CString strPath, int x, int y)
{
      IStream *pStm; 
      CFileStatus fstatus; 
      CFile file; 
      LONG cb; 
      if (file.Open(strPath,CFile::modeRead)&&file.GetStatus(strPath,fstatus)&&((cb = fstatus.m_size) != -1)) 
      { 
            HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, cb); 
            LPVOID pvData = NULL; 
            if (hGlobal != NULL) 
            { 
                  pvData = GlobalLock(hGlobal);
                  if (pvData != NULL) 
                  { 
                        file.Read(pvData, cb); 
                        GlobalUnlock(hGlobal); 
                        CreateStreamOnHGlobal(hGlobal, TRUE, &pStm); 
                  }
            }
      }
      else
            return false;
      //显示JPEG和GIF格式的图片，GIF只能显示一帧，还不能显示动画，
      //要显示动画GIF请使用ACTIVE控//件。
      IPicture *pPic;
      //load image from file stream
      if(SUCCEEDED(OleLoadPicture(pStm,fstatus.m_size,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 = (double)pDC->GetDeviceCaps(HORZRES)*(double)hmWidth/((double)pDC->GetDeviceCaps(HORZSIZE)*100.0); 
            fY = (double)pDC->GetDeviceCaps(VERTRES)*(double)hmHeight/((double)pDC->GetDeviceCaps(VERTSIZE)*100.0); 
            //use render function display image
            if(FAILED(pPic->Render(*pDC,x,y,(DWORD)fX,(DWORD)fY,0,hmHeight,hmWidth,-hmHeight,NULL))) 
            {
                  pPic->Release();
                  return false;
            }
            pPic->Release();
      } 
      else 
            return false; 
      return true;
}

使用方法：

在对话框上放一个cstatic控件IDC_STC_DUMMY，调整控件大小使得图片能够完全显示

CDC* pDC = GetDlgItem(IDC_STC_DUMMY)->GetDC();
ShowJpgGif(pDC,"aa.jpg",0,0);