Checkbox checked at startup.

Hi Guys, in these days I'm working to a gui to some code I wrote.
I've not done it before (not with MSVC++) but seems I?ve done something looking into exemples.
The last thing I must solve is to have a checkbox automaticly checked when I run the program but i did't found any exemple or document on it.
Any idea?

I'd like to set to checked as I set the default value for olter elements like:


something like:


Many thanks to who will answer.

BTW: please don't write strong things since I'm newbie in this and I need this thing just for this interface.

Who is Participating?
jhanceConnect With a Mentor Commented:
Assuming you have a checkbox with an ID of IDC_CHECKBOX do in your OnInitDialog:

CButton *pButton = (CButton *)GetDlgItem(IDC_CHECKBOX);
zuppyAuthor Commented:
I?ve just tried.
It compiles, but when I try to exec it it crashes with an error on MFC42D.DLL.
This is the code I've pasted:

CButton *pButton = (CButton *)GetDlgItem(hDlg,IDC_CHECK2_SMOOTH);


(you forgot the "hDlg" handler)

Any idea why?

I didn't forget anything. You posted this in the MFC topic area.  I guess I (foolishly) assumed this was an MFC program.

I was referring to CWnd::GetDlgItem() and NOT ::GetDlgItem() as you have used.  If you are going to use ::GetDlgItem() then you must pass it the HWND for the dialog containing the checkbox.
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2 things to note:
a.) jhance's suggestion is absolutely correct
b.) you can make it a bit more safe, or at least easier to debug. Use the following code instead:

CButton* pButton = static_cast<CButton*>( GetDlgItem( IDC_CHECK2_SMOOTH ) );
ASSERT( NULL != pButton );

If you call this function at a time where the button hasn't been created you will be notified by a dialog popping up when you are running in debug mode. The ASSERT()-function will not be compiled into the release build.
Hello zuppy

1) Is your ID correctly spelled?
2) does it exist on the dialog or window you are have handle off?
3) If you use GetDlgItem with 2 parameters, what you
get back will be HWND, so you can never cast it into
a CButton! Instead use function SetCheck with 2 parameters
or you might have to use SendMessage function to
change button styles.
4) In any case, it is good idea to check for NULL
return value before using it as shown by fl0yd.

Why don't you add a control to your checkbox using class wizard and then you can intilaize it to checked in OnInitDaialog()

zuppyAuthor Commented:
Hi guys i've solved using all suggestion given by everybody.
So to who I have to give points? ;-)

Whose answer was closest or contained your
your info?
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