[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
7 h+ `+ J9 {* T// 打开文件
HANDLE hFile;
' S/ ], B5 B6 X! s. Hif( ( hFile = ::CreateFile( strName ,true ) ), GENERIC_READ, FILE_SHARE_READ
, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_SEQUENTIAL_SCAN, NULL
) ^' k. T4 Q5 Q9 f! k8 |  M" Q! T) ) != INVALID_HANDLE_VALUE )
{
$ b# G2 e! V+ J: R4 W// 创建文件流
DWORD dwSize = DWORD( ::GetFileSize( hFile, NULL ) );
ASSERT( dwSize != -1 );
HGLOBAL hMemory = ::GlobalAlloc( GMEM_MOVEABLE, dwSize );
6 T$ @' M7 F; |ASSERT( hMemory != NULL );
5 D; A0 O# T: `2 xLPVOID pData = ::GlobalLock( hMemory );
ASSERT( pData != NULL );
DWORD dwCount;
::ReadFile( hFile, pData, dwSize, &dwCount, NULL );
# x- H+ p& B0 G2 g::GlobalUnlock( hMemory );
1 V, Q: f) S7 p" Y* J- T, e- qIStream * pStream = NULL;
  G1 l5 P8 x# N; M- w6 ^1 ]9 x::CreateStreamOnHGlobal( hMemory, TRUE, &pStream );
ASSERT( pStream != NULL );
6 d7 r" N& B( T9 h8 A; c// 从流中装入图片
* T: t( K+ q' S0 ZIPicture * pPicture = NULL;
" t- i% ^6 n3 u7 K: {1 w. aif( SUCCEEDED( ::OleLoadPicture( pStream, dwSize, TRUE, IID_IPicture,( LPVO
, {8 v  U' C! R) Y6 ~# @3 l+ y2 F8 JID* )&pPicture ) ) )
  |  I1 z0 ?8 h2 P) q; K{
1 d; P3 K" `) C2 R) Q// 向DC中绘图
OLE_XSIZE_HIMETRIC hmWidth;
- P+ A2 p5 t* S$ ~, W/ jOLE_YSIZE_HIMETRIC hmHeight;
# G8 H( K, a+ O0 u3 n1 `+ FpPicture->get_Width( &hmWidth );
pPicture->get_Height( &hmHeight );
pPicture->Render( hDC, 0, 0, 300, 300, 0, hmHeight, hmWidth, -hmHeight, NU
; V& G' }5 d- B& ]LL );
pPicture->Release();
1 X7 S8 ^% }9 U% W! [}
# O( i* c( m( N0 n( b4 ?1 R// 释放流和文件
pStream->Release();
' v; C7 X0 a  F, d::CloseHandle( hFile );
}