raw display

Used some online code example to put a little project to display raw image. The display does not seem to work.
For some purposes, I like this to work with a dialog based MFC project.XDVView is derived from CScrollView.
see OnInitDialog() and OnDraw(CDC* pDC).8bit 768x756

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Originally Posted by lch2

For some purposes, I like this to work with a dialog based MFC project.XDVView is derived from CScrollView.

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Could you define these"some purposes" to work with a dialog based rather than a SDI MFC project?
BTW, your code in XDVView::OnDraw has a resource leak (you call ::GetDC but do not call the ReleaseDC)

Got a dialog based MFC that is 100% done. Would be nicer to draw a few raw images continuously using a pop up dialog. Worked with SDI long time ago and do not see major point to port everything to SDI. This is not a major show just a few continuous captures and displays. image is 8bit grayscale. There are many similar reasons in the forum.

There was a bug in filling the buffer. Now, my problem is, I can not scroll to view entire image. it re-draws the top half only. It needs improvements. attached.

any one, any suggestion, help?.

If it is in a CScrollView derived class - try SetScrollSizes

Used the setscrollsizes already. I just can not get the scroll bar sizes right. Probably the OnDraw and SetScrollSizes needs changes.

Your OnDraw implementation seems to be strange (not to say incorrect!)

Quote:

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Code:

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void XDVView::OnDraw(CDC* dc)
{
        CDocument* pDoc = GetDocument();

        int ht;
        int wh;
        ht = Pbmp->bmiHeader.biHeight;
        wh = Pbmp->bmiHeader.biWidth;

        HDC hdc=::GetDC(m_hWnd);

        SetDIBitsToDevice(hdc,0,0,(DWORD)wh,(DWORD)ht,0,0,0,
        (WORD)ht,buf,Pbmp,DIB_RGB_COLORS);

}

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Why do you SetDIBitsToDevice to ::GetDC() rather than to CDC* dc) passed in by the framework?
Besides, you leak the resources since you do not call the ReleaseDC

already added: SetDIBitsToDevice(dc->GetSafeHdc(),.. and Release(dc); Won't have any performance drawback?. OnDraw is called continuously.

You only need to ReleaseDC if you called GetDC. But in your pseudo-code I see no need in GetDC at all!

OnDraw is NOT called continuously. Is is called only some repaint is needed (usually in response to InvalidateRect.

since i use SetDIBitsToDevice(dc->GetSafeHdc(),.. , then I do not need to call the ReleaseDC, right?. If the buffer passed to the SetDIBitsToDevice is refreshed, I have to call the Invalidate to (refresh the) display the current data in the buffer, right?. I wrote a bit of code to test this. I like to read some inputs as well.

Quote:

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Originally Posted by lch2

since i use SetDIBitsToDevice(dc->GetSafeHdc(),.. , then I do not need to call the ReleaseDC, right?

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Yep!

Quote:

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Originally Posted by lch2

If the buffer passed to the SetDIBitsToDevice is refreshed, I have to call the Invalidate to (refresh the) display the current data in the buffer, right?

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Yep!

for some reason, had to call the RedrawWindow to update the window properly. Invalidate() would not update it after each buffer updates.

Yes. It can happen when some other messages (system considers them more "important" than WM_PAINT) are in the message queue.

How can I enlarge the filed of view to show more lines without scrolling or with less scrolling?.

Did you try SetScrollSizes?

yes, i am using SetScrollSizes. Also, I like to maximize the dialog with the frame box and with that stretch the display area to cover the maximized dialog. right now only the dialog expands but the display area does not.