C / C++ / MFC

Re: CString or LPCTSTR...which one's better?

13-Jun-03 2:07

It depends what type of operations you nedd to perform on the strings. If you use MFC anyway, and if you need to manipulate strings like deleting characters, and another size-modifying functions, it's best to use CStrings, you rife will be much easier and you can avoid spme bugs.
But if you just need to pass unmodified strings to another functions, LPTSTR is more efficient.

rrrado

TeeBee30313-Jun-03 2:10

TeeBee303

13-Jun-03 2:10

CString uses TCHAR internally. (LPTSTR)
so if you define _UNICODE, TCHAR is defined as wchar_t so CString is also using unicode

where is the problem?
Smile | :)

CEdit and the Return key

CodeBrain13-Jun-03 1:42

13-Jun-03 1:42

I have a single line edit control and a class derived from CEdit. Now I want that the CFormView class which contains the edit control gets informed if the user presses the Return key if the Edit control has the input focus.
I've tried to react on the NM_RETURN notification in my form view but I don't get the event in the form view (must I use reflection in my edit class?).
Then I tried to capture the VK_RETURN key in the OnChar method of my edit class, but the OnChar method seems not to get any VK_RETURN events.

So what would be the best way to get my form view informed if the user presses the return key in my edit control?

Thanks in advance.

rrrado13-Jun-03 1:58

13-Jun-03 1:58

Try to set "Want return" style in resource editor for edit control,
i think NM_RETURN could start working then

rrrado

CodeBrain13-Jun-03 2:23

13-Jun-03 2:23

No luck, it seems not to work. I've already tried it and it makes no difference. The documentation also says that "Want return" only effects multiline edit controls.

Johann Gerell13-Jun-03 2:17

Johann Gerell

13-Jun-03 2:17

Subclass the edit control like this:

pOldEditWindowProc = (WNDPROC)::SetWindowLong(hWndEdit, GWL_WNDPROC, (LONG)EditWindowProc);
.
.
.
LRESULT CALLBACK EditWindowProc(HWND aHwnd, UINT aMsg, WPARAM aWp, LPARAM aLp)
{
    if(Return was pressed) ::SendMessage(::GetParent(aHwnd), aMsg, aWp, aLp); 

    return ::CallWindowProc(pOldEditWindowProc, aHwnd, aMsg, aWp, aLp);
}

--
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Roger Allen13-Jun-03 2:17

Roger Allen

13-Jun-03 2:17

The other way to handle this is in PreTranslateMessage()

if (pMsg->message == WM_KEYDOWN && pMsg->wParam == VK_RETURN && GetFocus() == GetDlgItem(ID_OF_CONTROL))
{
// handle it here!
}

Roger Allen
Sonork 100.10016

Were you different as a kid? Did you ever say "Ooohhh, shiny red" even once? - Paul Watson 11-February-2003

CodeBrain13-Jun-03 3:47

13-Jun-03 3:47

I have added some additional code, which seems to work now. But I still find it a bit ugly to perform the check in the application class. But that's ugly windows Dead | X|

Would be nice if someone could add feedback, if this code is correct or not, e.g. the
CWinApp::PreTranslateMessage(pMsg); part.

Thanks for your help!

BOOL CMyApp::PreTranslateMessage(MSG* pMsg)
{
if (pMsg->message == WM_KEYDOWN && pMsg->wParam == VK_RETURN))
{
HWND hFocus = GetFocus();
CFrameWnd* pFrmWnd = dynamic_cast<cframewnd*>(GetMainWnd()); if (pFrmWnd == NULL)
{
ASSERT(FALSE);
}

CWnd* pTarget = pFrmWnd->GetActiveView()->GetDlgItem(IDC_EDIT_X);
// We should test, if an active view exists, if we are not sure...
HWND hTarget = NULL;
if (pTarget != NULL)
{
hTarget = pTarget->GetSafeHwnd();
}
if (hFocus == hTarget)
{
// Do what you want
}
return 1;
}
else
{
return CWinApp::PreTranslateMessage(pMsg);
}
}

Ryan Binns13-Jun-03 4:05

Ryan Binns

13-Jun-03 4:05

I would have overridden PreTranslateMessage() in your edit control, and just sent a message to the parent:

BOOL CMyEdit::PreTranslateMessage(MSG *pMsg)
{
    if((pMsg->message == WM_KEYDOWN) && (pMsg->wParam == VK_RETURN))
    {
        CWnd *pParent = GetParent();
        if(pParent != NULL)
            pParent->SendMessage(WM_KEYDOWN, VK_RETURN, pMsg->lParam);
    }
    else
        return CEdit::PreTranslateMessage(pMsg);
}

And then just handle WM_KEYDOWN like normal in the parent and check for Enter being pressed. If you need to handle it in your main frame window, then use AfxGetMainWnd() instead of GetParent().

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

CodeBrain13-Jun-03 4:44

How do you prevent a window from being minimized?

13-Jun-03 4:44

Thank you for the hint, I will try it.

Abin13-Jun-03 1:21

Abin

13-Jun-03 1:21

I want to prevent a window from being minimized(currently it minimizes itself as soon as it is no longer the foreground window), I think I need to write a hook, but I don't know what message I need to capture... can some one please give some detailed solution? Thanks a lot.

Re: How do you prevent a window from being minimized?

rrrado13-Jun-03 1:41

Re: How do you prevent a window from being minimized?

13-Jun-03 1:41

What about to create that window without minimize button ? Smile | :)

And remove minimize command from it's system menu ?

rrrado

Abin13-Jun-03 1:44

Abin

13-Jun-03 1:44

The target window was not created by me, it's a third party progrram, I just hate it when it keeps minimizing itself so...

How to find active control ?

rrrado13-Jun-03 0:31

Re: How to find active control ?

13-Jun-03 0:31

I'm handling WM_CONTEXTMENU message in dialog, invoked by keyboard. It contains two List controls. How to find which one (if any) is activated ?
I tried to get HWND of active window by ::GetActiveWindow()
and comnpare it to HWNDs of list controls get by ::GetDlgItem().
But they are never equal, even if some of the List controls is focused.
Any idea how to do this ?

Thanks

rrrado

User 665813-Jun-03 1:20

User 6658

13-Jun-03 1:20

Have you tried GetFocus()?

regards

modified 12-Sep-18 21:01pm.

Re: How to find active control ?

rrrado13-Jun-03 1:39

13-Jun-03 1:39

Yes, the same result. But I've solved that,
i'm handling listctrls' NM_SETFOCUS and NM_KILLFOCUS and i remember which was focused last Smile | :)

But another mystery for me is, why NM_RETURN from list control is never sent Confused | :confused:

I look at messages in Spy++, it's always only finding default dialog item and invoking that.

rrrado

Getting Call Stack info

Ceri13-Jun-03 0:09

Ceri

13-Jun-03 0:09

Hi,

Does naybody know how to get the call stack programaticly in a function

Thanks
Ceri

Neville Franks13-Jun-03 0:20

Neville Franks

13-Jun-03 0:20

MFC has a function named AfxDumpStack() or something like that. There are several articles here on CP for crash handling and dumping the stack. Also see John Robbins's BugSlayer articles on MSDN.

Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com

Ceri13-Jun-03 0:53

Ceri

13-Jun-03 0:53

Hi,

Thanks for the reply.

This is no good to me for 2 reasons.

1.
I am not using MFC

2.
If i where then i dont want to output it, i need to actaully do something with the stack frames.

I have managed it now by using __asm blocks and using the esp pointer.

Not sure i you can help with this question.

Do you know how to get the module name or HMODULE that is mapped for a particualt section of memory. e.g.

A module is loaded at address 0x01000000. There is a function in that module at address 0x01000123. How can I determine which module that 0x01000123 is inside

Many Thanks
Ceri

Neville Franks13-Jun-03 1:26

Neville Franks

13-Jun-03 1:26

There are plenty of good articles around on walking the stack.
http://msdn.microsoft.com/msdnmag/issues/02/06/Bugslayer/default.aspx[^]
http://www.michaelmoser.org/stk.htm[^]
http://msdn.microsoft.com/msdnmag/issues/02/03/Hood/default.aspx[^]
http://www.microsoft.com/msj/0497/hood/hood0497.aspx[^]

Search MSDN and Google and you'll find lots more.

Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com