[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
2 \7 x0 r% B. O  BHANDLE hFile;
) M* z( L* R7 A! \( ?; ^& mif( ( hFile = ::CreateFile( strName ,true ) ), GENERIC_READ, FILE_SHARE_READ
1 Z' v2 o, ^' I* H0 k# N, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_SEQUENTIAL_SCAN, NULL
' u2 ^7 V! ~! S1 D; H) ) != INVALID_HANDLE_VALUE )
{
1 C- F$ I3 [+ z6 M8 w) V) u// 创建文件流
/ {+ ~) X) x2 TDWORD dwSize = DWORD( ::GetFileSize( hFile, NULL ) );
1 \* G& i' N+ v) ^/ X$ `ASSERT( dwSize != -1 );
HGLOBAL hMemory = ::GlobalAlloc( GMEM_MOVEABLE, dwSize );
ASSERT( hMemory != NULL );
# u5 |0 |6 C+ b* VLPVOID pData = ::GlobalLock( hMemory );
4 ^% W' R% ~! `# ~ASSERT( pData != NULL );
DWORD dwCount;
: y* |7 F+ d' L& j& \2 v::ReadFile( hFile, pData, dwSize, &dwCount, NULL );
" Y( h5 K+ a' E; G5 q2 n::GlobalUnlock( hMemory );
IStream * pStream = NULL;
::CreateStreamOnHGlobal( hMemory, TRUE, &pStream );
& ^9 {" J: B+ PASSERT( pStream != NULL );
( u6 C$ W9 Z$ S2 J; {// 从流中装入图片
IPicture * pPicture = NULL;
! F9 q% d; {& _8 {1 Y2 ~( O/ k9 Bif( SUCCEEDED( ::OleLoadPicture( pStream, dwSize, TRUE, IID_IPicture,( LPVO
ID* )&pPicture ) ) )
{
+ I% k  u' S: V2 L8 O2 M0 v, ?+ l// 向DC中绘图
& }! v, S# E- m1 rOLE_XSIZE_HIMETRIC hmWidth;
OLE_YSIZE_HIMETRIC hmHeight;
2 E4 r) k1 |+ v; {" tpPicture->get_Width( &hmWidth );
pPicture->get_Height( &hmHeight );
* J' }2 x" b) `pPicture->Render( hDC, 0, 0, 300, 300, 0, hmHeight, hmWidth, -hmHeight, NU
# S' u. u1 f+ `, ], wLL );
. g. S1 C9 P- l" ]+ `; Y% r2 z% Q7 YpPicture->Release();
2 ~6 g! N" I2 I6 f2 ^. T; o# p}
// 释放流和文件
pStream->Release();
::CloseHandle( hFile );
}