使用VC实现JPG图片加载
发布时间：2010/5/10 11:04:14 来源：城市学习网 编辑：ziteng
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!");
