Do not ever call OnDraw. The framework will call it for you. You will see
that OnUpdate calls Invalidate. That causes the framework to call OnDraw.
The sample code you are hoping to imitate is very different from OnDraw.
passed to OnDraw. Instead of using pDrawItemStruct coordinates you will
Thanks for everyone gives the suggestions.
I'm only want to show the thumbnail image, and there is no other needs.
My working now is let the OnUpdate()(other view will call the DOC's
UpdateAllViews() ) in the view(for show the thumbnail image) calling the
OnDraw() and draw the image.
First problem is that I don't know this is the correct way of doing so.
Sencond problem is that I can't draw the thumbnail image by imitating
other's source code("ImageTool" from code project) from the Internet. The
source code is as following:
//************ code ******************
The project include a memdc.h which the author writes himself.
void CPreviewDlg::OnDrawItem( int nIDCtl, LPDRAWITEMSTRUCT
lpDrawItemStruct )
{
if( lpDrawItemStruct->itemAction & ODA_DRAWENTIRE )
{
CMemDC *pMemDC = NULL;
pMemDC = new CMemDC( lpDrawItemStruct->hDC );
lpDrawItemStruct->hDC = pMemDC->m_hDC;
CRect rect; GetClientRect( rect );
HBRUSH hBrush = ::CreateSolidBrush( RGB(255, 255, 255) );
::FillRect( lpDrawItemStruct->hDC, rect, hBrush );
DeleteObject( hBrush );
CImageToolDoc *pDoc = (CImageToolDoc*)
((CMainFrame*)AfxGetMainWnd())->GetActiveDocument();
if( pDoc->m_pSelectedImage != NULL )
{
Graphics graphics( lpDrawItemStruct->hDC );
graphics.SetInterpolationMode(InterpolationModeHighQualityBicubic);
graphics.DrawImage( pDoc->m_pSelectedImage,
Rect( lpDrawItemStruct->rcItem.left,
lpDrawItemStruct->rcItem.top,
lpDrawItemStruct->rcItem.right - lpDrawItemStruct->rcItem.left,
lpDrawItemStruct->rcItem.bottom - lpDrawItemStruct->rcItem.top));
}
delete pMemDC;
}
}
//************ code ******************
The problem is that there's no "int nIDCtl" and "LPDRAWITEMSTRUCT
lpDrawItemStruct" parameter for OnDraw()!!!
"Tom Serface" wrote:
The only argument for using a form view is if there would ever be a
chance
of needing more controls added. Resizing a picture control in a formview
is
easy and looks about the same as the solution you are demonstrating. If
OP
is sure they will never need any other controls (like description info,
path
info, ability to select image, etc.) then this method is likely easier to
implement (although not a lot easier).
Tom
"AliR (VC++ MVP)" <AliR@online.nospam> wrote in message
news:aQIbl.1210$PE4.32@nlpi061.nbdc.sbc.com...
I disagree with doing it this way. If he is only going to display an
image
on a window why go through the overhead of CFormView and a CStatic. Why
not simply draw the image himself in the views paint routine. This way
he
has full control, if later he wants to add scrolling he can do that
(where
if he had a CFormView with a static control it would be difficult), and
also can avoid flickering by overriding the erasebackground message.
void CMyView::OnPaint()
{
CPaintDC dc(this);
CMemDC MemDC;
MemDC.CreateCompatibleDC(&dc);
int Saved = MemDC.SaveDC();
MemDC.SelectObject(m_Bmp);
//calculate X, and Y based on the window size and Width and
Height
of bitmap
....
dc.BitBlt(X,Y,Width,Height,&MemDC,0,0,SRCCOPY);
MemDC.RestoreDC(Saved);
}
AliR.