[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
// 打开文件
$ {; R) S0 }) G# o# GHANDLE hFile;
if( ( hFile = ::CreateFile( strName ,true ) ), GENERIC_READ, FILE_SHARE_READ
, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_SEQUENTIAL_SCAN, NULL
) ) != INVALID_HANDLE_VALUE )
- P" ?% _% g; w; |{
// 创建文件流
" q* ]2 {& G- a2 B7 x. A- d3 SDWORD dwSize = DWORD( ::GetFileSize( hFile, NULL ) );
ASSERT( dwSize != -1 );
  v) {0 x$ H( l0 W9 V1 }HGLOBAL hMemory = ::GlobalAlloc( GMEM_MOVEABLE, dwSize );
* X- W  Y! ^- o( y7 ^7 ?ASSERT( hMemory != NULL );
# ?: G" D3 j9 Y, ], x# SLPVOID pData = ::GlobalLock( hMemory );
ASSERT( pData != NULL );
9 K2 C2 u8 Q4 f- {2 |8 NDWORD dwCount;
::ReadFile( hFile, pData, dwSize, &dwCount, NULL );
( W/ m% E+ E& m, C7 ?" A::GlobalUnlock( hMemory );
IStream * pStream = NULL;
1 `+ [# [% ^# o; C9 Z9 b::CreateStreamOnHGlobal( hMemory, TRUE, &pStream );
6 ?4 l, X2 m" F- vASSERT( pStream != NULL );
// 从流中装入图片
5 B+ j4 t) E  y! w" o: H2 YIPicture * pPicture = NULL;
if( SUCCEEDED( ::OleLoadPicture( pStream, dwSize, TRUE, IID_IPicture,( LPVO
0 \" a4 P( ]2 S" Q( N" ~0 |ID* )&pPicture ) ) )
{
- k- o  ~- v; B2 T6 M// 向DC中绘图
8 ?) q6 l: R# t2 K. S5 m( }$ Y7 TOLE_XSIZE_HIMETRIC hmWidth;
OLE_YSIZE_HIMETRIC hmHeight;
0 z) ?9 n7 e0 HpPicture->get_Width( &hmWidth );
pPicture->get_Height( &hmHeight );
pPicture->Render( hDC, 0, 0, 300, 300, 0, hmHeight, hmWidth, -hmHeight, NU
LL );
( d# x# m9 ^# U4 r" GpPicture->Release();
}
; L' ?; t  }* v- k// 释放流和文件
pStream->Release();
4 c" ]0 |! U- X+ f+ P5 x* I# ~" x! S::CloseHandle( hFile );
3 N3 G! c& M, Q0 f+ c}