[收藏]读取JPEG和GIF图像的简单方法

天云上人

CString strName; // 文件名
HDC hDC; // 绘图句柄
' V9 y. {' W; c( d// 打开文件
HANDLE hFile;
- M1 W+ z! U2 j2 nif( ( hFile = ::CreateFile( strName ,true ) ), GENERIC_READ, FILE_SHARE_READ
* e1 d' n; e9 N- P: H, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_SEQUENTIAL_SCAN, NULL
) ) != INVALID_HANDLE_VALUE )
{
  x$ O" D% s' z// 创建文件流
DWORD dwSize = DWORD( ::GetFileSize( hFile, NULL ) );
: M) q& \$ M  I' i5 m( @ASSERT( dwSize != -1 );
HGLOBAL hMemory = ::GlobalAlloc( GMEM_MOVEABLE, dwSize );
ASSERT( hMemory != NULL );
LPVOID pData = ::GlobalLock( hMemory );
* H% N8 N) U2 b6 O" N! ?ASSERT( pData != NULL );
DWORD dwCount;
& V* H, a# ]- w::ReadFile( hFile, pData, dwSize, &dwCount, NULL );
4 j- r: O8 s& l( {1 {  h5 Q: Y::GlobalUnlock( hMemory );
IStream * pStream = NULL;
::CreateStreamOnHGlobal( hMemory, TRUE, &pStream );
ASSERT( pStream != NULL );
, ]/ T% V, C: G; ?// 从流中装入图片
8 X( o/ v$ H) B9 `% g5 X  f# ]IPicture * pPicture = NULL;
, x% U1 [8 ]* E5 V7 bif( SUCCEEDED( ::OleLoadPicture( pStream, dwSize, TRUE, IID_IPicture,( LPVO
9 H9 j8 p( M( A  R- v' A0 jID* )&pPicture ) ) )
7 v4 q5 }6 V+ U2 N) Z, l3 N{
0 F  H  @5 Y! |( H$ Q, I// 向DC中绘图
OLE_XSIZE_HIMETRIC hmWidth;
OLE_YSIZE_HIMETRIC hmHeight;
* f% ?3 {* }* P8 g( y0 y3 gpPicture->get_Width( &hmWidth );
pPicture->get_Height( &hmHeight );
pPicture->Render( hDC, 0, 0, 300, 300, 0, hmHeight, hmWidth, -hmHeight, NU
) ]0 V; B& i# A9 VLL );
pPicture->Release();
: g0 q0 D/ i1 z" z0 D( d3 a- |}
// 释放流和文件
pStream->Release();
+ a! B& W. i: \' L4 h" R::CloseHandle( hFile );
: }' e, _% p  P5 n6 X& `, X) k}