使用VC实现JPG图片加载

使用VC实现JPG图片加载：

在OnDraw（）函数中添加如下的代码，并在工程目录下放入test.jpg的图片。

IPicture *pPic;

IStream *pStm;

CFileStatus fstatus;

CFile file;

LONG cb;

if (file.Open("test.jpg",CFile::modeRead)&&file.GetStatus("test.jpg", fstatus)&& ((cb = fstatus.m_size) != -1))

{

HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, cb);

LPVOID pvData = NULL;

if (hGlobal != NULL)

{

if ((pvData = GlobalLock(hGlobal)) != NULL)

{

file.ReadHuge(pvData, cb);

GlobalUnlock(hGlobal);

CreateStreamOnHGlobal(hGlobal, TRUE, &pStm);

if(SUCCEEDED(OleLoadPicture(pStm,fstatus.m_size,TRUE,IID_IPicture,(LPVOID*)&pPic)))

{

OLE_XSIZE_HIMETRIC hmWidth;

OLE_YSIZE_HIMETRIC hmHeight;

pPic->get_Width(&hmWidth);

pPic->get_Height(&hmHeight);

double fX,fY;

CRect rect;

GetClientRect(rect);

fX=rect.Width();

fY=rect.Height();

//fX = (double)pDC->GetDeviceCaps(HORZRES)*(double)hmWidth/((double)pDC->GetDeviceCaps(HORZSIZE)*100.0);

//fY = (double)pDC->GetDeviceCaps(VERTRES)*(double)hmHeight/((double)pDC->GetDeviceCaps(VERTSIZE)*100.0);

if(FAILED(pPic->Render(*pDC,0,0,(DWORD)fX,(DWORD)fY,0,hmHeight,hmWidth,-hmHeight,NULL))) AfxMessageBox("Failed To Render The picture!");

pPic->Release();

}

else

AfxMessageBox("Error Loading Picture From Stream!");

}

}

}

else

AfxMessageBox("Can't Open Image File!");