MFC对话框显示JPEG图片

nq19860409 2009-04-10 10:53:16

运行对话框没有出现图片，我是否需要在对话框上添加控件吗，光凭以下代码就能显示12.jpg图片吗，以下代码应该放哪呢
CDC* pDC;
pDC=GetDC();
ShowPicture(pDC,"c:\\12.jpg",0,0,200,100);



#define   HIMETRIC_INCH 2540   

LPPICTURE   gpPicture;  

void CCDMADlg::ShowPicture(CDC *pDC, CString m_strBRoute, int x, int y, int width, int height)

  {   

  HANDLE   hFile =CreateFile(m_strBRoute,   GENERIC_READ,   0,   NULL,   OPEN_EXISTING,   0,   NULL);   

  _ASSERTE(INVALID_HANDLE_VALUE != hFile);   

    

  //   取得文件大小   

  DWORD   dwFileSize   =   GetFileSize(hFile,   NULL);   

  _ASSERTE(-1   !=   dwFileSize);   

  LPVOID   pvData   =   NULL;   

  //根据文件大小分配内存   

  HGLOBAL   hGlobal   =   GlobalAlloc(GMEM_MOVEABLE,   dwFileSize);   

  _ASSERTE(NULL   !=   hGlobal);   

  pvData   =   GlobalLock(hGlobal);   

  _ASSERTE(NULL   !=   pvData);   

  DWORD   dwBytesRead   =   0;   

  //读取文件并存入全局内存   

  BOOL   bRead   =   ReadFile(hFile,   pvData,   dwFileSize,   &dwBytesRead,   NULL);   

  _ASSERTE(FALSE   !=   bRead);   

  GlobalUnlock(hGlobal);   

  CloseHandle(hFile);   

  LPSTREAM   pstm   =   NULL;   

  //   通过全局内存创建   IStream*   的指针   

  HRESULT   hr   =   CreateStreamOnHGlobal(hGlobal,   TRUE,   &pstm);   

  _ASSERTE(SUCCEEDED(hr)   &&   pstm);   

  //通过图形文件创建IPicture   对象   

  if   (gpPicture)   

  gpPicture->Release();   

  hr   =   OleLoadPicture(pstm,   dwFileSize,   FALSE,   IID_IPicture,   (LPVOID   *)&gpPicture);   

  _ASSERTE(SUCCEEDED(hr)   &&   gpPicture);   

  pstm->Release();   

  HDC   hdc;   

  hdc=pDC->GetSafeHdc();   

  if   (gpPicture)   

  {   

  //   取得图片的宽和高   

  long   hmWidth;   

  long   hmHeight;   

  gpPicture->get_Width(&hmWidth);   

  gpPicture->get_Height(&hmHeight);   

  //宽高转换为象素   

  int   nWidth =   MulDiv(hmWidth,   GetDeviceCaps(hdc,   LOGPIXELSX),   HIMETRIC_INCH);   

  int   nHeight =   MulDiv(hmHeight,   GetDeviceCaps(hdc,   LOGPIXELSY),   HIMETRIC_INCH);   

  RECT   rc;   

  GetClientRect(&rc);/*取得客户区*/   

  gpPicture->Render(hdc,   x,y,   (int)height*hmWidth/hmHeight,height,   0,   hmHeight,   hmWidth,   -hmHeight,   &rc);   

  /*显示图片*/   

  }   

    

  }