CButton in child window

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February 2nd, 2011, 05:04 AM
nitinmalapalli

CButton in child window

Hello all,

I'm working on a little app and this is the first time I'm coding using MFC and VC++.

I have a CFrameWnd derived main window as well as a CWnd derived child window. I wish to place a CBitmapButton in the child window. I create a CBitmapButton object, call it's create function with WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON | BS_OWNERDRAW but it refuses to show up where I need it to. On the other hand, when I create it in the main window, it shows up with no problem. So essentially, I can't seem to make a visible button (as a child) in the child window of a main window but I seem to be able to do it in the main window.

What is going on? I'll be greatly appreciative of your advice, of course.

Thanks a lot!
February 2nd, 2011, 05:19 AM
VictorN

Re: CButton in child window

What exactly is this "CWnd derived child window"?
How do you create your button? Please show your code (don't forget using Code tags!)
February 2nd, 2011, 06:58 AM
nitinmalapalli

Re: CButton in child window

Hello Victor, thanks for replying.

The CWnd derived child window is <Code> CMainChildWnd : public CWnd </Code>

This is how I create my button:

<Code>

class CMainChildWnd : public CWnd
{
public:
CBitmapButton cbut1;

protected:
afx_msg int OnCreate(LPCREATESTRUCT lpcs);
};

</Code>

The above is the class, as you can see.

<Code>

//Create
//Load bitmaps
cbut1.LoadBitmaps(IDB_BITMAP1);
//Done
cbut1.Create(_T("Add"), WS_CHILD | BS_OWNERDRAW | BS_PUSHBUTTON | WS_VISIBLE, CRect(110,20,140,50), this, 1);
//done

</Code>

That's in CMainChildWnd::OnCreate(LPCREATESTRUCT lpcs).

I repeat, the button is completely invisible. However, it does turn up if I put the very same code in the parent CMainWnd : public CFrameWnd object i.e, in the parent window.

Cheers.
February 2nd, 2011, 07:21 AM
VictorN

Re: CButton in child window

1. You have to use [B][...][/B] for the tags, not <...>.
2. Does this code in the class CMainChildWnd

Code:

cbut1.Create(_T("Add"), WS_CHILD | BS_OWNERDRAW | BS_PUSHBUTTON | WS_VISIBLE, CRect(110,20,140,50), this, 1);

executed? Did you debug it to be sure it is executed?
February 2nd, 2011, 07:43 AM
nitinmalapalli

Re: CButton in child window

Sorry about that, ... it is!

Yes, I'm quite sure it compiles. The same line in the parent window creates and displays the required button...
February 2nd, 2011, 07:53 AM
VictorN

Re: CButton in child window

Quote:

Originally Posted by nitinmalapalli

Yes, I'm quite sure it compiles. ..

I don't ask you whether it "compiles". Sure it is! Otherwise you couldn't run your App.
I ask you whether this line of code is executed! Set a break point to this line and then start your App from IDE using F5. If it is executed then it would be nide to know what this cbut1.Create(...) returns...

Besides, you have hardcoded the CRect coordinates of the button. But will this rect lie in the client area of CMainChildWnd window?
February 2nd, 2011, 10:18 AM
nitinmalapalli

Re: CButton in child window

Quote:

Originally Posted by VictorN

I don't ask you whether it "compiles". Sure it is! Otherwise you couldn't run your App.
I ask you whether this line of code is executed! Set a break point to this line and then start your App from IDE using F5. If it is executed then it would be nide to know what this cbut1.Create(...) returns...

Besides, you have hardcoded the CRect coordinates of the button. But will this rect lie in the client area of CMainChildWnd window?

I set a breakpoint as you suggested and ran it using F5. I have no idea about this procedure but I made these observations:

1.) It did not break at that line, if that was expected.

2.) It said exactly:

'Temp.exe': Loaded 'C:\Users\Nitin\Documents\Visual Studio 2005\Projects\Temp\debug\Temp.exe', Symbols loaded.
'Temp.exe': Loaded 'C:\Windows\System32\ntdll.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\kernel32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\KernelBase.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\user32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\gdi32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\lpk.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\usp10.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\msvcrt.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\advapi32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\sechost.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\rpcrt4.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\sspicli.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\cryptbase.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\comdlg32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\shlwapi.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\winsxs\x86_microsoft.windows.common-controls_6595b64144ccf1df_5.82.7600.16385_none_ebf82fc36c758ad5\comctl32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\shell32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\winspool.drv', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\ole32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\oleaut32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\imm32.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\msctf.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\uxtheme.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\dwmapi.dll', No symbols loaded.
'Temp.exe': Loaded 'C:\Windows\SysWOW64\ole32.dll', No symbols loaded.
'Temp.exe': Unloaded 'C:\Windows\SysWOW64\ole32.dll'
'Temp.exe': Loaded 'C:\Windows\winsxs\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.7600.16385_none_421189da2b7fabfc\comctl32.dll', No symbols loaded.
Detected memory leaks!
Dumping objects ->
{84} client block at 0x025A7930, subtype c0, 84 bytes long.
a CPaintDC object at $025A7930, 84 bytes long
Object dump complete.
The program '[1400] Temp.exe: Native' has exited with code 0 (0x0).

3.) It did not trace/output the return value of the Create function at all.

4.) I later checked the "Hit Count" of the breakpoint, which turned out to be 0.
February 2nd, 2011, 11:07 AM
VictorN

Re: CButton in child window

Quote:

Originally Posted by nitinmalapalli

I set a breakpoint as you suggested and ran it using F5. I have no idea about this procedure but I made these observations:

1.) It did not break at that line, if that was expected.

Well, it is the answer on your question why "the button is completely invisible" being placed on the "CWnd derived child window": This button is not created!
February 2nd, 2011, 12:42 PM
nitinmalapalli

Re: CButton in child window

Quote:

Originally Posted by VictorN

Well, it is the answer on your question why "the button is completely invisible" being placed on the "CWnd derived child window": This button is not created!

That is astonishing to hear! Could you please tell me the possible reasons why the button may not be created? For example, can I not create buttons in CMainChildWnd::OnCreate(LPCREATESTRUCT lpcs)? What all could be preventing the execution of the line?

Thanks a lot for the guidance so far!
February 2nd, 2011, 12:54 PM
GCDEF

Re: CButton in child window

Your codepath obviously doesn't lead to that line of code.
February 2nd, 2011, 12:58 PM
nitinmalapalli

Re: CButton in child window

Quote:

Originally Posted by GCDEF

Your codepath obviously doesn't lead to that line of code.

Thanks for replying, GCDEF.
I'm sorry, but how couldn't it? It's all nestled in the OnCreate function. Surely, that'll always get executed? Ideally, in which member function should I create a button?
February 2nd, 2011, 01:12 PM
GCDEF

Re: CButton in child window

Quote:

Originally Posted by nitinmalapalli

Thanks for replying, GCDEF.
I'm sorry, but how couldn't it? It's all nestled in the OnCreate function. Surely, that'll always get executed? Ideally, in which member function should I create a button?

Use your debugger to find out.
February 2nd, 2011, 01:25 PM
VictorN

Re: CButton in child window

Quote:

Originally Posted by nitinmalapalli

T... For example, can I not create buttons in CMainChildWnd::OnCreate(LPCREATESTRUCT lpcs)? What all could be preventing the execution of the line?

Are you sure this CMainChildWnd::OnCreate(...) is ever called? :confused:
February 2nd, 2011, 01:30 PM
nitinmalapalli

Re: CButton in child window

Quote:

Originally Posted by VictorN

Are you sure this CMainChildWnd::OnCreate(...) is ever called? :confused:

Quite sure. Some other lines are getting executed in the same function!
February 2nd, 2011, 01:34 PM
VictorN

Re: CButton in child window

Please, show your actual code of this function. (don't forget using Code tags!)
Then point to to lines that are executed and the ones that are not. :cool:
February 2nd, 2011, 01:34 PM
nitinmalapalli

Re: CButton in child window

Update: Actually, I am not sure that the function is being called. But i assume OnCreate is definitely called!
February 2nd, 2011, 01:35 PM
GCDEF

Re: CButton in child window

Quote:

Originally Posted by nitinmalapalli

Update: Actually, I am not sure that the function is being called. But i assume OnCreate is definitely called!

Don't assume anything. Verify it with the debugger.
February 2nd, 2011, 10:47 PM
nitinmalapalli

Re: CButton in child window

It turns out, and I'm ashamed of myself, that I had the statements after the "return 0;" of the int OnCreate(...)

I'm very grateful to you for having helped me out though, I never really had got around to using the Debugger. This was a learning experience, nevertheless.

Thanks very much, GCDEF and Victor!