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Only Numbers

P: n/a
Hey all!
I'm kinda new to VB but not to programin'.
So I know what it is like when you are asked trivial questions.
Could some1 please tell me what the syntax would be 2 only allow numerical
data into a textbox. thankz in advanced -Ro

--------------------------------------------------------------------
" Reality is an illusion caused by lack of alcohol. "
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Jul 17 '05 #1
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9 Replies


P: n/a
Rowan Chapman wrote:
Hey all!
I'm kinda new to VB but not to programin'.
So I know what it is like when you are asked trivial questions.
Could some1 please tell me what the syntax would be 2 only allow numerical
data into a textbox. thankz in advanced -Ro

--------------------------------------------------------------------
" Reality is an illusion caused by lack of alcohol. "
--------------------------------------------------------------------


You could use isNumeric() in the Change, LostFocus or Validate event for
the textbox.
--
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GCS d-@ s:- a C++ ULS>++ P L+>+++ E- W++ N++ o? K- w(++)>+++$
!O M- V? PS PE Y+ PGP- t 5 X+ R- tv++ b+ DI D+ G e++ h+ r++ y+
------END GEEK CODE BLOCK------
Jul 17 '05 #2

P: n/a
From a previous post of mine...

I usually try and steer people away from using IsNumeric to "proof"
supposedly numeric text. Consider this (also see note at end of post):

ReturnValue = IsNumeric("($1,23,,3.4,,,5,,E67$)")

Most people would not expect THAT to return True. IsNumeric has some "flaws"
in what it considers a proper number and what most programmers are looking
for.

I had a short tip published by Pinnacle Publishing in their Visual Basic
Developer magazine that covered some of these flaws. Originally, the tip was
free to view but is now viewable only by subscribers.. Basically, it said
that IsNumeric returned True for things like -- currency symbols being
located in front or in back of the number as shown in my example (also
applies to plus, minus and blanks too); numbers surrounded by parentheses as
shown in my example (some people use these to mark negative numbers);
numbers containing any number of commas before a decimal point as shown in
my example; numbers in scientific notation (a number followed by an upper or
lower case "D" or "E", followed by a number equal to or less than 305 -- the
maximum power of 10 in VB); and Octal/Hexadecimal numbers (&H for
Hexadecimal, &O or just & in front of the number for Octal).

NOTE:
======
In the above example and in the referenced tip, I refer to $ signs and
commas and dots -- these were meant to refer to your currency, thousands
separator and decimal point symbols as defined in your local settings --
substitute your local regional symbols for these if appropriate.

As for the question about checking numbers, here are two functions that I
have posted in the past for similar questions..... one is for digits only
and the other is for "regular" numbers:

Function IsDigitsOnly(Value As String) As Boolean
IsDigitsOnly = Len(Value) > 0 And _
Not Value Like "*[!0-9]*"
End Function

Function IsNumber(ByVal Value As String) As Boolean
' Leave the next statement out if you don't
' want to provide for plus/minus signs
If Value Like "[+-]*" Then Value = Mid$(Value, 2)
IsNumber = Not Value Like "*[!0-9.]*" And _
Not Value Like "*.*.*" And _
Len(Value) > 0 And Value <> "." And _
Value <> vbNullString
End Function

Rick - MVP
"Sado" <oi***@boingo.net> wrote in message
news:8V********************@newsb.telia.net...
Rowan Chapman wrote:
Hey all!
I'm kinda new to VB but not to programin'.
So I know what it is like when you are asked trivial questions.
Could some1 please tell me what the syntax would be 2 only allow numerical data into a textbox. thankz in advanced -Ro

--------------------------------------------------------------------
" Reality is an illusion caused by lack of alcohol. "
--------------------------------------------------------------------


You could use isNumeric() in the Change, LostFocus or Validate event for
the textbox.
--
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GCS d-@ s:- a C++ ULS>++ P L+>+++ E- W++ N++ o? K- w(++)>+++$
!O M- V? PS PE Y+ PGP- t 5 X+ R- tv++ b+ DI D+ G e++ h+ r++ y+
------END GEEK CODE BLOCK------

Jul 17 '05 #3

P: n/a
> Hey all!
I'm kinda new to VB but not to programin'.
So I know what it is like when you are asked trivial questions.
Could some1 please tell me what the syntax would be 2 only allow numerical
data into a textbox. thankz in advanced -Ro


First off, what do you mean by "numerical data"... digits only or floating
point numbers? Next, by "only allow", do you mean *while* the user is typing
in his/her entry? Or do you mean a way to check it *after* the entry is
completed (like from the Click event of an "I'm Done" type of
CommandButton)? Most people consider the latter to be a better interface for
the user.

Rick - MVP
Jul 17 '05 #4

P: n/a

"Rowan Chapman" <rn*******@bigpond.com> wrote in message
news:j5******************@news-server.bigpond.net.au...
Hey all!
I'm kinda new to VB but not to programin'.
So I know what it is like when you are asked trivial questions.
Could some1 please tell me what the syntax would be 2 only allow numerical
data into a textbox. thankz in advanced -Ro


If you want to totally not permit user to type non numeric entries into the
textbox, then you have to intercept the keypress. Something like this (you
can adjust it to your needs):

Private Sub Text1_KeyPress(KeyAscii As Integer)
Call num(KeyAscii)
End Sub

Private Sub num(KeyAscii As Integer)
' allow backspace and decimal
If KeyAscii = 8 Or KeyAscii = 9 Or KeyAscii = Asc(".") Then Exit Sub
' if not a number, zero out the key (nothing shows up)
KeyAscii = IIf(Chr$(KeyAscii) Like "[0-9]", KeyAscii, 0)
End Sub
Jul 17 '05 #5

P: n/a
"Raoul Watson" <Wa*****@IntelligenCIA.com> wrote in message news:<qe*****************@nwrdny03.gnilink.net>...
"Rowan Chapman" <rn*******@bigpond.com> wrote in message
news:j5******************@news-server.bigpond.net.au...
Hey all!
I'm kinda new to VB but not to programin'.
So I know what it is like when you are asked trivial questions.
Could some1 please tell me what the syntax would be 2 only allow numerical
data into a textbox. thankz in advanced -Ro


If you want to totally not permit user to type non numeric entries into the
textbox, then you have to intercept the keypress.


that doesn't prevent users from pasting data
Jul 17 '05 #6

P: n/a

"Bob Butler" <bu*******@earthlink.net> wrote in message
news:fa*************************@posting.google.co m...
"Raoul Watson" <Wa*****@IntelligenCIA.com> wrote in message

news:<qe*****************@nwrdny03.gnilink.net>...
"Rowan Chapman" <rn*******@bigpond.com> wrote in message
news:j5******************@news-server.bigpond.net.au...
Hey all!
I'm kinda new to VB but not to programin'.
So I know what it is like when you are asked trivial questions.
Could some1 please tell me what the syntax would be 2 only allow numerical data into a textbox. thankz in advanced -Ro


If you want to totally not permit user to type non numeric entries into the textbox, then you have to intercept the keypress.


that doesn't prevent users from pasting data


Rick already addressed the validation after the data is entered.
Jul 17 '05 #7

P: n/a
> > > > Hey all!
> I'm kinda new to VB but not to programin'.
> So I know what it is like when you are asked trivial questions.
> Could some1 please tell me what the syntax would be 2 only allow numerical > data into a textbox. thankz in advanced -Ro
>

If you want to totally not permit user to type non numeric entries
into
the textbox, then you have to intercept the keypress.


that doesn't prevent users from pasting data


Rick already addressed the validation after the data is entered.


Actually, Bob's point is quite valid. Why would you attempt to block most
non-digits, but still have to check afterward in order to take some action.
Put another way, why would you want to block me from typing a non-digit, but
permit me to paste one in? You would either block all attempts to input
non-digits or permit them during data entry and validate the entry after the
user is finished entering it (in response to a "Done" button or, maybe, the
focus attempting to leave the TextBox). My comment was meant to side with
the "let the user enter anything they want and parse it afterwards" crowd.
If you want to block non-digits while typing or pasting, the following will
do that...

Dim LastPosition As Long

Private Sub Text1_Change()
Static LastText As String
Static SecondTime As Boolean
If Not SecondTime Then
With Text1
If .Text Like "*[!0-9]*" Then
Beep
SecondTime = True
.Text = LastText
.SelStart = LastPosition
Else
LastText = .Text
End If
End With
End If
SecondTime = False
End Sub

Private Sub Text1_MouseDown(Button As Integer, _
Shift As Integer, X As Single, Y As Single)
With Text1
LastPosition = .SelStart
'Place any other MouseDown event code here
End With
End Sub

Private Sub Text1_KeyPress(KeyAscii As Integer)
With Text1
LastPosition = .SelStart
'Place any other KeyPress checking code here
End With
End Sub

Rick - MVP
Jul 17 '05 #8

P: n/a

"Rick Rothstein" <ri************@NOSPAMcomcast.net> wrote in message
news:3s********************@comcast.com...
> > Hey all!
> > I'm kinda new to VB but not to programin'.
> > So I know what it is like when you are asked trivial questions.
> > Could some1 please tell me what the syntax would be 2 only allow numerical
> > data into a textbox. thankz in advanced -Ro
> >
>
> If you want to totally not permit user to type non numeric entries

into
the
> textbox, then you have to intercept the keypress.

that doesn't prevent users from pasting data


Rick already addressed the validation after the data is entered.


Actually, Bob's point is quite valid. Why would you attempt to block most
non-digits, but still have to check afterward in order to take some

action. Put another way, why would you want to block me from typing a non-digit, but permit me to paste one in? You would either block all attempts to input
non-digits or permit them during data entry and validate the entry after the user is finished entering it (in response to a "Done" button or, maybe, the focus attempting to leave the TextBox). My comment was meant to side with
the "let the user enter anything they want and parse it afterwards" crowd.
If you want to block non-digits while typing or pasting, the following will do that...

Dim LastPosition As Long

Private Sub Text1_Change()
Static LastText As String
Static SecondTime As Boolean
If Not SecondTime Then
With Text1
If .Text Like "*[!0-9]*" Then
Beep
SecondTime = True
.Text = LastText
.SelStart = LastPosition
Else
LastText = .Text
End If
End With
End If
SecondTime = False
End Sub

Private Sub Text1_MouseDown(Button As Integer, _
Shift As Integer, X As Single, Y As Single)
With Text1
LastPosition = .SelStart
'Place any other MouseDown event code here
End With
End Sub

Private Sub Text1_KeyPress(KeyAscii As Integer)
With Text1
LastPosition = .SelStart
'Place any other KeyPress checking code here
End With
End Sub

Rick - MVP


Excellent.. that's the way to do it (with a solution) but a post such as
"that doesn't prevent ..." doesn't quite help the original poster does it?
Jul 17 '05 #9

P: n/a
Thanks all, your insight/input was really helpful.

--------------------------------------------------------------------
" Reality is an illusion caused by lack of alcohol. "
--------------------------------------------------------------------

"Rowan Chapman" <rn*******@bigpond.com> wrote in message
news:j5******************@news-server.bigpond.net.au...
Hey all!
I'm kinda new to VB but not to programin'.
So I know what it is like when you are asked trivial questions.
Could some1 please tell me what the syntax would be 2 only allow numerical
data into a textbox. thankz in advanced -Ro

--------------------------------------------------------------------
" Reality is an illusion caused by lack of alcohol. "
--------------------------------------------------------------------


Jul 17 '05 #10

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