C / C++ / MFC

17-Dec-03 21:18

Hello guys,
I am still having trouble to catch "Enter" (Return) key press from a PC keyobard in my app. I think the problem mainly comes from the fact that the app has a parent dialog with serveral embedded child dialogs (only one child dialog is shown at a time on the app window, different child dialog is shown using ShowWindow(SW_SHOW), ShowWindow(SW_HIDE).

Preferrably, I want the child dialogs to catch the "Enter" key press. So what I did, was first, "return 0" in the parent class' OnInitDialog() and set the focus to the appearing child's DDX control, say a CButton, in the child class' OnShowWindow().

With the above method, I can get the focus set (using SetFocus()) to each desired CButton in the child dialogs and I can cycle through the buttons (if there are multiple) in each shown child dialog using arrow keys. However, none of the buttons will not respond to "Enter" key, but only "Spacebar" key to perform OnBnClicked() function. If I "tab" to the button that belong to the parent dialog, pressing the "Enter" key will call the OnBnCliked(). Can anyone explain why?

Also, I tried to see if the Enter key is caught in the child class by overriding its OnOk() or OnKeyDown() but the key pressed doesn't seem to go through them either.

tiaozi18-Dec-03 2:27

tiaozi

18-Dec-03 2:27

i don't understand you! but i think this may be help you:

BOOL CMyCTIDlg::PreTranslateMessage(MSG* pMsg)
{
// TODO: Add your specialized code here and/or call the base class
if(pMsg->message==WM_KEYDOWN)
if(pMsg->wParam==VK_ESCAPE||pMsg->wParam==VK_RETURN)
return true;

return CDialog::PreTranslateMessage(pMsg);
}

J.B.18-Dec-03 5:20

18-Dec-03 5:20

Thanks alot for the reply, taiozi.

And apologies for the badly phrased post, I wrote that in a rush. I have rewritten it. Would appreciate if you could give it one more read and see if you can understand it now Smile | :)

However, the PreTranslateMessage() you mention here might be what I am looking for, I will try that in my child dialogs' classes. Will report back.

Thanks again

J.B.18-Dec-03 6:02

18-Dec-03 6:02

Thanks tiaozi,

with your help (the code), I can correctly catch the Enter key press(VK_RETURN) and tell if it's caught by the parent dialog or the embedded child chialog. Now I realise when the app was initially load, the key press is always caught by the parent, although a button in the child dialog has been highlighted (here I'd think so the focus is set to the child dialog?).

Do you know how I can correctly set the focus to child dialog when the app is loaded? I've tried two different ways, none of them seem to work.

One is to place pChildDlg->SetFocus() in the parent class' OnInitDialog(). pChildDlg is the pointer to the child dialog that is showing.

Two is to place SetFocus() in the child class' OnShowWindow(), whether to the child itself (thus this->SetFocus();) or a control (in my case, to a CButton). Here as I mentioned earlier, when I SetFocus() to the CButton, I can see the button is highlighted as the app window is initially loaded. But when I hit "Enter" key, this input message is still caught by the parent? Confused | :confused:

J.B.18-Dec-03 6:25

18-Dec-03 6:25

OK, I got it working, with the second method (after some fix). I forgot to put ON_WM_SHOWWINDOW() message map in. D'Oh! | :doh:

VC++ Method

Ming Yan17-Dec-03 21:04

Ming Yan

17-Dec-03 21:04

I know that TextOut method helps displays strings...what if i want to display integer/float? Do I have to convert it to string n use TextOut? Or is there another available method?

Thank you

Abebe17-Dec-03 21:37

Abebe

17-Dec-03 21:37

i'm not sure if TextOut directely accepts integers, but you can use the 'Format' method of CString to construct a string from an integer (or float, double etc.). Hope this helps.

Er zit een korstje op mijn aars.

Ming Yan17-Dec-03 21:40

Ming Yan

17-Dec-03 21:40

Thanks for d reply...just to confirm. So, there is no other method to display integers than to convert it to string. Is it?

Thanks again.

Balkrishna Talele18-Dec-03 0:03

Balkrishna Talele

18-Dec-03 0:03

char buff[25];
sprintfbuff,"%d",m_yourInteger);
pdc->TextOut(buff);

hope this works for you, if you need some other stuff, do let me know.
regards
balkrishna talele

Rowan Seymour18-Dec-03 0:04

Rowan Seymour

18-Dec-03 0:04

BOOL TextOutF(HDC hDC, int x, int y, LPCTSTR szFmt, ...)
{
TCHAR szOutput[512];
va_list args;
va_start(args, szFmt);
_vsntprintf(szOutput, 512, szFmt, args);
va_end(args);

return TextOut(hDC, x, y, szOutput, _tcslen(szOutput));
}

Now you can write:

int nMyInt = 34;
TextOutF(hDC, 0, 0, "my int = %d", nMyInt);

Output:

"my int = 34"