[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
HANDLE hFile;
if( ( hFile = ::CreateFile( strName ,true ) ), GENERIC_READ, FILE_SHARE_READ
, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_SEQUENTIAL_SCAN, NULL
" N4 Q: g* C" _. n9 O) ) != INVALID_HANDLE_VALUE )
+ Z8 [0 E4 g$ y! j4 \: Q{
0 u! {# v- N4 d$ X! o. f# e1 \// 创建文件流
( p2 k) |" G3 p9 C# N2 ]DWORD dwSize = DWORD( ::GetFileSize( hFile, NULL ) );
: ]8 l4 O; o9 e2 @ASSERT( dwSize != -1 );
HGLOBAL hMemory = ::GlobalAlloc( GMEM_MOVEABLE, dwSize );
ASSERT( hMemory != NULL );
LPVOID pData = ::GlobalLock( hMemory );
! T: @6 M& w$ x9 a1 JASSERT( pData != NULL );
DWORD dwCount;
::ReadFile( hFile, pData, dwSize, &dwCount, NULL );
" C; C+ w8 L8 A2 X; A  T( [::GlobalUnlock( hMemory );
) G8 r5 [7 F$ f% v: C. G6 BIStream * pStream = NULL;
::CreateStreamOnHGlobal( hMemory, TRUE, &pStream );
ASSERT( pStream != NULL );
; R/ j1 i7 i; z( y// 从流中装入图片
IPicture * pPicture = NULL;
if( SUCCEEDED( ::OleLoadPicture( pStream, dwSize, TRUE, IID_IPicture,( LPVO
/ f; ]! T$ Q/ \' r4 p* |ID* )&pPicture ) ) )
- D  Q  n1 w: Q( r9 i. E1 c( D{
9 P+ y$ K' ]9 w  @  ]% C9 K// 向DC中绘图
) Y  W2 S6 p3 }4 {OLE_XSIZE_HIMETRIC hmWidth;
OLE_YSIZE_HIMETRIC hmHeight;
pPicture->get_Width( &hmWidth );
4 e' Z6 `; v; w8 b0 N' p2 _pPicture->get_Height( &hmHeight );
7 f3 U4 N" f  Y# E" {pPicture->Render( hDC, 0, 0, 300, 300, 0, hmHeight, hmWidth, -hmHeight, NU
LL );
( @% g! i  P1 Z4 bpPicture->Release();
/ y) M0 c7 S0 C8 ^; K}
* F% b+ L5 `8 ~// 释放流和文件
1 v/ U) n9 }+ OpStream->Release();
) r  _: d; y* E3 H' O::CloseHandle( hFile );
}