viusal basic input validation integer - basic.visual

code_wrong wrote:

> Visual Basic (not dot net)
> what is the best way to check the User has entered an integer into an
> InputBox?

Use a masked input box that rejects invalid entries at the keystroke.

Look up "masked input" - there were lots of options for VB6. 6 years ago.

And upgrade to a dynamic OO language as soon as you can. VB6 will bring you
down.

--
Phlip
http://www.greencheese.org/ZeekLand <-- NOT a blog!!!

"Phlip" <phlip2005@gmail.com> wrote in message
news:ia2Nf.17971$NS6.5433@newssvr30.news.prodigy.com...
> code_wrong wrote:
>
>> Visual Basic (not dot net)
>> what is the best way to check the User has entered an integer into an
>> InputBox?
>
> Use a masked input box that rejects invalid entries at the keystroke.
>
> Look up "masked input" - there were lots of options for VB6. 6 years ago.
>
> And upgrade to a dynamic OO language as soon as you can. VB6 will bring
> you
> down.

unfortunately I am restricted to using inputbox() ... why? .. if I change
the method for input now, the students will likely will be traumatised ..
these are very early days

> Visual Basic (not dot net)
> what is the best way to check the User has entered an integer into an
> InputBox?

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

Here are revisions to the above functions that deal with the local settings
for decimal points (and thousand's separators) that are different than used
in the US (this code works in the US too, of course).

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

I'm not as concerned by the rejection of entries that include one or more
thousand's separators, but we can handle this if we don't insist on the
thousand's separator being located in the correct positions (in other words,
we'll allow the user to include them for their own purposes... we'll just
tolerate their presence).

Function IsNumber(ByVal Value As String) As Boolean
Dim DP As String
Dim TS As String
' Get local setting for decimal point
DP = Format$(0, ".")
' Get local setting for thousand's separator
' and eliminate them. Remove the next two lines
' if you don't want your users being able to
' type in the thousands separator at all.
TS = Mid$(Format$(1000, "#,###"), 2, 1)
Value = Replace$(Value, TS, "")
' 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" & DP & "]*" And _
Not Value Like "*" & DP & "*" & DP & "*" And _
Len(Value) > 0 And Value <> DP And _
Value <> vbNullString
End Function

Rick

code_wrong wrote:
> Visual Basic (not dot net)
> what is the best way to check the User has entered an integer into an
> InputBox?
>
> isNumeric() checks for a numeric value .. but does not notify of numbers
> with decimal places
> inputBox returns a string so I could check for decimal point??? this seems
> like overkill
>
> The value returned can be asigned into an Integer type and then a Single
> type ... the two can be compared .. but still this does not complain about
> numbers with decimal places if the fractional part is zero
>
> what is the simple solution?
>
> cw
>
>

What you can do on a text box control that is being used for only
numbers is use the Keypress Event and check the key being pressed. If
it's a numeric key 0-9, you accept the keypress. If the key is not a
numeric key 0-9, the you cancel or don't accept the keypress. I recall
ASCII code 0 or something like that cancels key-code from a key press so
that it's not accepted.

You just write a Keypress event routine that accepts numeric keys or
possibly a control key like the ESC-Key, Backspace-Key or ( Tab-key set
focus to the next control), take the appropriate actions on the
control-keys, cancel any key that's not 0-9 and only accept the 0-9 keys.

Duane

> What you can do on a text box control that is being used for only
> numbers is use the Keypress Event and check the key being pressed. If
> it's a numeric key 0-9, you accept the keypress. If the key is not a
> numeric key 0-9, the you cancel or don't accept the keypress. I recall
> ASCII code 0 or something like that cancels key-code from a key press so
> that it's not accepted.
>
> You just write a Keypress event routine that accepts numeric keys or
> possibly a control key like the ESC-Key, Backspace-Key or ( Tab-key set
> focus to the next control), take the appropriate actions on the
> control-keys, cancel any key that's not 0-9 and only accept the 0-9 keys.

You can't take appropriate action on "true" control keys in the KeyPress
event; that requires the KeyUp or KeyDown event. And if you don't handle all
of the keystrokes that allow a user to Paste data (and the Mouse events that
allow it too), then your user will be able to Paste non-digits into the
TextBox. And, after all of that, I think you will still have missed one or
two places where the user can initiate a Paste operation.

Rick

Rick Rothstein [MVP - Visual Basic] wrote:
>>What you can do on a text box control that is being used for only
>>numbers is use the Keypress Event and check the key being pressed. If
>>it's a numeric key 0-9, you accept the keypress. If the key is not a
>>numeric key 0-9, the you cancel or don't accept the keypress. I recall
>>ASCII code 0 or something like that cancels key-code from a key press so
>>that it's not accepted.
>>
>>You just write a Keypress event routine that accepts numeric keys or
>>possibly a control key like the ESC-Key, Backspace-Key or ( Tab-key set
>>focus to the next control), take the appropriate actions on the
>>control-keys, cancel any key that's not 0-9 and only accept the 0-9 keys.
>
>
> You can't take appropriate action on "true" control keys in the KeyPress
> event; that requires the KeyUp or KeyDown event. And if you don't handle all
> of the keystrokes that allow a user to Paste data (and the Mouse events that
> allow it too), then your user will be able to Paste non-digits into the
> TextBox. And, after all of that, I think you will still have missed one or
> two places where the user can initiate a Paste operation.
>
> Rick
>
>

You may be right I don't recall. However, I have used Keyup, Keydown,
Keypress and Mouse events. In the real world or in accounting
appliactions in business solutions in corporations where I have applied
the numeric only solution, it's worked like a champ on pure data entry
applications where the numbers had to be banged in - there is no cutting
and pasting.

It's something the poster is going to have to figure out for his or
herself as to the best approach.

Duane

Rick ...

Is not: Not Value Like "*[!0-9]*" ... redundant?

--

Randy Birch
MS MVP Visual Basic
http://vbnet.mvps.org/

Please reply to the newsgroups so all can participate.




"Rick Rothstein [MVP - Visual Basic]" <rickNOSPAMnews@NOSPAMcomcast.net>
wrote in message news:-cSdnbZbLfZ3JZnZnZ2dnUVZ_tGdnZ2d@comcast.com...
> Visual Basic (not dot net)
> what is the best way to check the User has entered an integer into an
> InputBox?

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

Here are revisions to the above functions that deal with the local settings
for decimal points (and thousand's separators) that are different than used
in the US (this code works in the US too, of course).

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

I'm not as concerned by the rejection of entries that include one or more
thousand's separators, but we can handle this if we don't insist on the
thousand's separator being located in the correct positions (in other words,
we'll allow the user to include them for their own purposes... we'll just
tolerate their presence).

Function IsNumber(ByVal Value As String) As Boolean
Dim DP As String
Dim TS As String
' Get local setting for decimal point
DP = Format$(0, ".")
' Get local setting for thousand's separator
' and eliminate them. Remove the next two lines
' if you don't want your users being able to
' type in the thousands separator at all.
TS = Mid$(Format$(1000, "#,###"), 2, 1)
Value = Replace$(Value, TS, "")
' 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" & DP & "]*" And _
Not Value Like "*" & DP & "*" & DP & "*" And _
Len(Value) > 0 And Value <> DP And _
Value <> vbNullString
End Function

Rick

"code_wrong" <tac@tac.co.uk> wrote in message
news:4404ac4c$1_3@mk-nntp-2.news.uk.tiscali.com...
> Visual Basic (not dot net)
> what is the best way to check the User has entered an integer into an
> InputBox?
>
> isNumeric() checks for a numeric value .. but does not notify of numbers with
> decimal places
> inputBox returns a string so I could check for decimal point??? this seems
> like overkill
>
> The value returned can be asigned into an Integer type and then a Single type
> ... the two can be compared .. but still this does not complain about numbers
> with decimal places if the fractional part is zero
>
> what is the simple solution?
>

"simple solution" is always a relative term in this NG

For integers, I would do this test, which deals with fractional entries as well:

Private Sub Command1_Click()
Dim A As Single
Dim B As Long
Dim C As Single
Dim bNum As Boolean
Dim sInput As String

sInput = InputBox("enter an integer", , "0")
bNum = IsNumeric(sInput)
If bNum Then
A = CSng(sInput)
B = CLng(A)
C = CSng(B)
End If
If bNum And C = A Then
MsgBox "good dog, you entered " & B
Else
MsgBox "How is " & sInput & " an integer?"
End If

End Sub

That way, the user can enter 3E7 if they want, a perfectly valid way of entering
30,000,000

Steve Gerrard wrote:

> MsgBox "How is " & sInput & " an integer?"

As a user, seeing sophomoric crap like that get through gives me a very low
opinion of the programmer on the other side.

For the OP; handle errors at keystroke time or at turn-around time (when the
field blurs, or when the current page submits). Then if the error is
complex, write text into a special field on the form. If the error is
simple, beep and turn its field red.

Contact with a user should be as sensitive and gentle as possible, to avoid
looking like the average VB interface.

--
Phlip
http://www.greencheese.org/ZeekLand <-- NOT a blog!!!