Re: Why JPG display only with 16 color in Dialog?
How did you determine that it's using 16 colors?
How many colors does your display show?
You don't seem to be setting up the palette. I suspect on high-color
systems, it would appear okay.
--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com
<ckkwan@my-deja.com> wrote in message
news:1155983445.451222.78450@h48g2000cwc.googlegroups.com...
Any clue? The code is attached below.
TIA.
void CCardDlg::LoadAndDisplayJpeg()
{
long Len;
CFile File;
HGLOBAL hglob = NULL;
HBITMAP hbm = NULL;
CPaintDC dc(this);
try
{
File.Open(_T("\\tmp\\YanYan.jpg"), CFile::modeRead);
Len = File.GetLength();
hglob = GlobalAlloc(GMEM_MOVEABLE, Len + 1);
if (hglob == NULL) CGException::ThrowLastError();
try
{
File.Read(GlobalLock(hglob), Len);
}
catch(...)
{
GlobalUnlock(hglob);
throw;
}
GlobalUnlock(hglob);
hbm = LoadJpeg(hglob);
// Draw the Bitmap
CDC mdc;
CRect rect;
CBitmap *Bmp;
BITMAP bmp;
mdc.CreateCompatibleDC(NULL);
Bmp = CBitmap::FromHandle(hbm);
CBitmap *obmp = mdc.SelectObject(Bmp);
GetClientRect(&rect);
Bmp->GetBitmap(&bmp);
dc.StretchBlt(0, 0, rect.Width(), rect.Height(),
&mdc, 0, 0, bmp.bmWidth, bmp.bmHeight, SRCCOPY);
mdc.SelectObject(obmp);
m_Photo.DeleteObject();
m_Photo.CreateBitmapIndirect(&bmp);
// Free resource
GlobalFree(hglob);
hglob = NULL;
DeleteObject(hbm);
hbm = NULL;
GetDlgItem(IDC_SC_PHOTO)->Invalidate();
}
catch(...)
{
if (hglob != NULL) GlobalFree(hglob);
if (hbm != NULL) DeleteObject(hbm);
throw;
}
}
HBITMAP CCardDlg::LoadJpeg(HGLOBAL hglob) const
{
IStream *stream = NULL;
CreateStreamOnHGlobal(hglob, FALSE, &stream);
IPicture *pic;
OleLoadPicture(stream, 0, FALSE, IID_IPicture, (void**) &pic);
stream->Release();
HBITMAP hbm0 = NULL;
pic->get_Handle((OLE_HANDLE*) &hbm0);
// Now we make a copy of it into our own hbm
DIBSECTION dibs;
::GetObject(hbm0, sizeof(dibs), &dibs);
// if (dibs.dsBm.bmBitsPixel != 24)
// {
// pic->Release();
// return NULL;
// }
int w = dibs.dsBm.bmWidth, h = dibs.dsBm.bmHeight;
dibs.dsBmih.biClrUsed = 0;
dibs.dsBmih.biClrImportant = 0;
void *bits;
HDC sdc = ::GetDC(m_hWnd);
HBITMAP hbm1 = ::CreateDIBSection(sdc, (BITMAPINFO*) &dibs.dsBmih,
DIB_RGB_COLORS, &bits, 0, 0);
//
HDC hdc0 = ::CreateCompatibleDC(sdc);
HDC hdc1 = ::CreateCompatibleDC(sdc);
HGDIOBJ hold0 = ::SelectObject(hdc0, hbm0);
HGDIOBJ hold1 = ::SelectObject(hdc1, hbm1);
::BitBlt(hdc1, 0, 0, w, h, hdc0, 0, 0, SRCCOPY);
::SelectObject(hdc0, hold0);
::SelectObject(hdc1, hold1);
::DeleteDC(hdc0);
::DeleteDC(hdc1);
::ReleaseDC(m_hWnd, sdc);
pic->Release();
return hbm1;
}