[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
3 p' `' E. P9 E9 p6 W// 打开文件
4 t+ d1 N$ w9 K; S: V& \* iHANDLE hFile;
if( ( hFile = ::CreateFile( strName ,true ) ), GENERIC_READ, FILE_SHARE_READ
, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_SEQUENTIAL_SCAN, NULL
+ [8 c/ _: e! O6 d) ) != INVALID_HANDLE_VALUE )
{
// 创建文件流
/ }$ ^6 v$ z! u; a" UDWORD dwSize = DWORD( ::GetFileSize( hFile, NULL ) );
ASSERT( dwSize != -1 );
0 I' Y2 S2 i* a$ L: q0 fHGLOBAL hMemory = ::GlobalAlloc( GMEM_MOVEABLE, dwSize );
) Y4 W, ^# J* Q8 {3 L& C; F3 GASSERT( hMemory != NULL );
. c3 c) n9 Z6 R( QLPVOID pData = ::GlobalLock( hMemory );
ASSERT( pData != NULL );
; R' j% _( x. v" y3 }& cDWORD dwCount;
::ReadFile( hFile, pData, dwSize, &dwCount, NULL );
  T( ~2 I) V' u2 h% Q::GlobalUnlock( hMemory );
0 E3 G5 n- g; u+ PIStream * pStream = NULL;
::CreateStreamOnHGlobal( hMemory, TRUE, &pStream );
ASSERT( pStream != NULL );
// 从流中装入图片
9 w6 a) m6 H) h: I; U" _6 y8 rIPicture * pPicture = NULL;
if( SUCCEEDED( ::OleLoadPicture( pStream, dwSize, TRUE, IID_IPicture,( LPVO
9 H: ?& m, r' t5 G/ z3 eID* )&pPicture ) ) )
{
// 向DC中绘图
- V% @5 m3 C$ T3 v0 _4 c: BOLE_XSIZE_HIMETRIC hmWidth;
OLE_YSIZE_HIMETRIC hmHeight;
pPicture->get_Width( &hmWidth );
- J, ?, m! u$ z- zpPicture->get_Height( &hmHeight );
2 v/ R( y% I+ R6 h/ @! M& WpPicture->Render( hDC, 0, 0, 300, 300, 0, hmHeight, hmWidth, -hmHeight, NU
2 m" x5 y# P. N: MLL );
pPicture->Release();
/ L5 a0 y: c2 |/ A0 t$ n! U}
/ h; a4 f* ~. s, F0 ~// 释放流和文件
  _& G/ i' r8 N9 Z7 {+ |pStream->Release();
& ?* c2 z5 n/ t  Y, k::CloseHandle( hFile );
}