Re: How to validate CEdit only number input?

From:

"Tom Serface" <tom.nospam@camaswood.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Thu, 24 Apr 2008 06:03:46 -0700

Message-ID:

<0B8D2E6F-31CE-499E-9B2C-BBFEA1880E02@microsoft.com>

If all you want are numbers you can do what you're suggesting here. You
need to call the base class at the end of the routine CEdit::OnChar() rather
than call your own function again. The way you list it here you will just
loop for a really long time.
You could take a look at something like:

http://www.codeproject.com/KB/miscctrl/numspinctrl.aspx

Tom

"Landon" <Landon@discussions.microsoft.com> wrote in message
news:1955F261-A2DB-4335-B7B2-9E84119966D4@microsoft.com...

I use Visual C++ 4.2 Professional.

I want to validate so that user only able to input numeric values. I've
looked for the keydown notify message, but I could not find one.

I've tried to trap the input by deriving a new class named CEditExt from
CEdit and make OnChar event but it did not work, I've debugged it but when
I
press any non-numeric key, the program sequence did not entering the
OnChar
event.

What is wrong?

I've attached my codes below:

Thank you very much.

in .cpp file:

// CEditExt
IMPLEMENT_DYNAMIC(CEditExt, CEdit)

BEGIN_MESSAGE_MAP(CEditExt, CEdit)
ON_WM_CHAR()
END_MESSAGE_MAP()
// CEditExt ??????????????? ????????????

void CEditExt::OnChar( UINT nChar, UINT nRepCnt, UINT nFlags )
{
if( nChar < '0' || nChar > '9' )
{
if ( nChar != VK_BACK )
return;
}
CEditExt::OnChar( nChar, nRepCnt, nFlags );
}

in .h file:
class CEditExt : public CEdit
{
DECLARE_DYNAMIC( CEditExt )

public:
CEditExt();
virtual ~CEditExt();

protected:
DECLARE_MESSAGE_MAP()

public:
afx_msg void OnChar( UINT nChar, UINT nRepCnt, UINT nFlags );
};