IImagingFactory装如bitmap的问题

Question

我用CreateDIBSection创建了一张位图,请问怎样用IImagingFactory中的函数读取这张位图?

IImagingFactory *m_pimgfactory;
IImage *m_pimage;

CoInitializeEx(NULL,COINIT_MULTITHREADED);
CoCreateInstance(CLSID_ImagingFactory,
NULL,
CLSCTX_INPROC_SERVER,
IID_IImagingFactory,
(LPVOID*)&m_pimgfactory);
CDC dc;
BYTE *buffer=NULL;
dc.CreateCompatibleDC(GetDC());
BITMAPINFO bitmapinfo={0};
bitmapinfo.bmiHeader.biSize=sizeof(BITMAPINFOHEADER);
bitmapinfo.bmiHeader.biWidth=40;
bitmapinfo.bmiHeader.biHeight=40;
bitmapinfo.bmiHeader.biPlanes=1;
bitmapinfo.bmiHeader.biBitCount=24;

HBITMAP bitmap=CreateDIBSection(dc,&bitmapinfo,DIB_RGB_COLORS,(LPVOID *)&buffer,NULL,0);
dc.SelectObject(bitmap);
CPen pen(PS_SOLID,5,RGB(255,0,0));
dc.SelectObject(&pen);
dc.MoveTo(5,5);
dc.LineTo(35,35);
dc.MoveTo(35,5);
dc.LineTo(5,35);
pen.DeleteObject();

BITMAP bmp;
GetObject(bitmap,sizeof(BITMAP),&bmp);
CRect rc(0,0,40,40);

if(SUCCEEDED(m_pimgfactory->CreateImageFromBuffer(buffer,bmp.bmWidthBytes*bmp.bmHeight,BufferDisposalFlagNone,&m_pimage)))
m_pimage->Draw(GetDC()->m_hDC,&rc,NULL);

这是我的一段代码,可是就是画不出图