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Re: How do I add listboxes to a back buffer and use that?

leon de boer7-Apr-20 19:05

leon de boer

7-Apr-20 19:05

You are making a mountain out of a molehill.

First it was pre-compiled in the debug directory, you didn't have to compile anything
Second main.ccp is stock standard C++ code will compile on any C++ windows compiler
Third you can also just rename main.cpp to a main.c file remove a couple of "::" and it would compile on any C windows compiler

What I do now know is your level of programming knowledge which is useful if you want me to try and help you.

So basically I am reading your bitmap paint is drawing over the top of the listboxes and other windows, it would be useful to see the original code that creates the parent window. I am basically thinking you are trying to draw a bitmap where the coloured gradient occurs on my sample is that correct? Notice my listboxes draw over the top of that gradient and I could turn it to a bitmap if that helps you. I might throw up a sample doing that, note I will put just the main.c and the exe this time.

Update: new sample that draws the beatyy.jpg image under the listboxes .. is that what you are trying to do?
Just run the pre-compiled exe file to test
GitHub - LdB-ECM/ListPlayBmp: Windows list with background Image sample[^]
Or the more generic example
Windows_Samples/ListJpg1 at master · LdB-ECM/Windows_Samples · GitHub[^]

Anyhow lets take a couple of stabs at this

1) Check you have the WS_CLIPCHILDREN flags set on the parent window ... read what it does
Window Styles (Winuser.h) - Win32 apps | Microsoft Docs[^]

2.) If all else fails because you really have cocked something just invalidate them after you paint the background (that probably means after EndPaint in your WM_PAINT message handler).
Here hwnd refers to the handle of the child listbox window etc

InvalidateRect(hwnd, NULL, TRUE);

This explains why it forces the redraw to happen but don't use it unless you have to because it will cause the listbox to flash as it redraws and is a horrible hack.
InvalidateRect function (winuser.h) - Win32 apps | Microsoft Docs[^]

Now if you have to use 2 you have a horrible structural issue with your code and I will try to explain how to fix it because we need to get the bitmap background draw much earlier on in the paint process.

In vino veritas

modified 8-Apr-20 4:59am.

Re: How do I add listboxes to a back buffer and use that?

Richard MacCutchan7-Apr-20 21:58

Richard MacCutchan

7-Apr-20 21:58

Because you are still doing it wrong. Creating Windows applications that correctly display bitmaps, textboxes, listboxes etc., is standard and works all round the world. If you want multiple controls in a single Window then you must place them alongside, not on top of, each other. The best way to do that is to use a Dialog which is designed for exactly that purpose.

Re: How do I add listboxes to a back buffer and use that?

David Crow8-Apr-20 1:58

David Crow

8-Apr-20 1:58

PotatoSoup wrote:
...and place buttons and listboxes, etc. on that window...

Are you adding these controls at runtime?

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Re: How do I add listboxes to a back buffer and use that?

leon de boer8-Apr-20 4:03

leon de boer

8-Apr-20 4:03

He is doing it runtime, go to his first post you can see he is inserting the ListBox into the main window, that code will be in the WM_CREATE of a window or WM_INITDIALOG of a dialog.

I assumed in his rather crazy round about way what he was asking is to paint the ListBox to a memory DC rather than the screen DC.
He seems to be calling HDC "buffers" see his names ===> HDC_of_FRONT_BUFFER
Anyhow that is easy you just use the WM_PRINTCLIENT message which you subclass onto a class and handle it.
WM_PRINTCLIENT message (Winuser.h) - Win32 apps | Microsoft Docs[^]
You use that mainly for printing a screen capturing of a window or remote terminal programs where you need to send the screen data.

So I gave him an example that does that, but he either doesn't understand or he is doing something really strange.

In vino veritas

Re: How do I add listboxes to a back buffer and use that?

David Crow8-Apr-20 4:25

David Crow

8-Apr-20 4:25

I'm glad you understood it. I was just rolling rocks to see what crawled out.

basic MFC app

Calin Negru6-Apr-20 0:30

Calin Negru

6-Apr-20 0:30

I`m trying to build a barebones MFC app. I`m used to C# Forms, but I`m having a tough time in MFC though.
I`m creating a new MFC app in the New Project dialog and in the Wizard I pick Dialog based app as app type. However after creation I can`t open the resource (in the resource view) to fill it with controls.