[收藏]读取JPEG和GIF图像的简单方法

天云上人

CString strName; // 文件名
2 s; J& O( ]/ ?$ L0 s) J6 n- X- MHDC hDC; // 绘图句柄
// 打开文件
HANDLE hFile;
if( ( hFile = ::CreateFile( strName ,true ) ), GENERIC_READ, FILE_SHARE_READ
1 \, P0 h) x+ i8 n) ?! a, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_SEQUENTIAL_SCAN, NULL
1 t# |# E& j. b- ]3 i) ) != INVALID_HANDLE_VALUE )
{
// 创建文件流
DWORD dwSize = DWORD( ::GetFileSize( hFile, NULL ) );
+ l1 S0 o" ^  |: Y; p6 @ASSERT( dwSize != -1 );
HGLOBAL hMemory = ::GlobalAlloc( GMEM_MOVEABLE, dwSize );
- \0 V0 {; g* Z, Z. m: QASSERT( hMemory != NULL );
LPVOID pData = ::GlobalLock( hMemory );
ASSERT( pData != NULL );
DWORD dwCount;
* J# A& G& K& k5 W::ReadFile( hFile, pData, dwSize, &dwCount, NULL );
::GlobalUnlock( hMemory );
IStream * pStream = NULL;
::CreateStreamOnHGlobal( hMemory, TRUE, &pStream );
+ n6 t" f1 r2 j; P; g. cASSERT( pStream != NULL );
+ w+ F% Q/ K6 D; Y// 从流中装入图片
IPicture * pPicture = NULL;
if( SUCCEEDED( ::OleLoadPicture( pStream, dwSize, TRUE, IID_IPicture,( LPVO
ID* )&pPicture ) ) )
{
1 R- C$ I5 F* x) a4 N: g2 ~+ l: _// 向DC中绘图
- c# U' U* |1 o5 e. XOLE_XSIZE_HIMETRIC hmWidth;
% C6 H/ k9 V& M- F" wOLE_YSIZE_HIMETRIC hmHeight;
" N% \5 ^8 D+ fpPicture->get_Width( &hmWidth );
pPicture->get_Height( &hmHeight );
pPicture->Render( hDC, 0, 0, 300, 300, 0, hmHeight, hmWidth, -hmHeight, NU
LL );
! ?- l  ?, H% N/ |1 |1 cpPicture->Release();
}
// 释放流和文件
& @) O/ {. w) J) y7 L! a9 w4 [. mpStream->Release();
::CloseHandle( hFile );
}