将JPG图片绘制在对话框背景上：（这段代码绝对可以执行）

将JPG图片绘制在对话框背景上：  
   
  显示JPG图片的函数  
  void   CMyDlg::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*/  
  }  
  GlobalFree(hGlobal);  
   
  }  
   
  //在OnEraseBkgnd中  
  CRect   rc;  
  GetClientRect(&rc);  
  ShowPicture(pDC,strJpgPath,rc.left,rc.top,rc.Width(),   rc.Height());