Invalid Data?

[dfg]

I do some error checking on my textbox. The problem is that if I enter
a valid number, then backspace until the box is empty, my msgbox pops up
saying "Data Error". Is there a way to avoid this?

Also, if I enter invalid data and try to backspace through it, my "Data
Error" msgbox pops up. This is rather annoying. Does anyone have a
solution to this problem? I posted my code - I hope it formats correctly.

Thanks.
Private Sub txtAmtSold_Change()
If txtAmtSold = "" Then
mnuEditCalculate.Enabled = False
End If

If IsNumeric(txtAmtSold) Then
If Val(txtAmtSold) >= 1 And Val(txtAmtSold) _
<= 100 Then
mnuEditCalculate.Enabled = True
Else
mnuEditCalculate.Enabled = False
MsgBox "Error: Numbers must be in the range of 1 - 100",
vbExclamation, "Range Error"
End If
Else
mnuEditCalculate.Enabled = False
MsgBox "Data Must Be Numeric", vbExclamation, "Data Error"
End If
End Sub

[Randy Birch]

If you're not hung up on throwing message boxes every time someone makes an
error, just use this:

Private Sub txtAmtSold_Change()

mnuEditCal.Enabled = Len(txtAmtSold.Text) > 0 And _
IsNumeric(txtAmtSold) And _
Val(txtAmtSold.Text) >= 1 And _
Val(txtAmtSold.Text)

End Sub
--

Randy Birch
MVP Visual Basic
http://www.mvps.org/vbnet/
Please respond only to the newsgroups so all can benefit.
"dfg" <df*@dfg.net> wrote in message news:zl%mb.193461$6C4.13496@pd7tw1no...
: I do some error checking on my textbox. The problem is that if I enter
: a valid number, then backspace until the box is empty, my msgbox pops up
: saying "Data Error". Is there a way to avoid this?
:
: Also, if I enter invalid data and try to backspace through it, my "Data
: Error" msgbox pops up. This is rather annoying. Does anyone have a
: solution to this problem? I posted my code - I hope it formats correctly.
:
: Thanks.
:
:
: Private Sub txtAmtSold_Change()
: If txtAmtSold = "" Then
: mnuEditCalculate.Enabled = False
: End If
:
: If IsNumeric(txtAmtSold) Then
: If Val(txtAmtSold) >= 1 And Val(txtAmtSold) _
: <= 100 Then
: mnuEditCalculate.Enabled = True
: Else
: mnuEditCalculate.Enabled = False
: MsgBox "Error: Numbers must be in the range of 1 - 100",
: vbExclamation, "Range Error"
: End If
: Else
: mnuEditCalculate.Enabled = False
: MsgBox "Data Must Be Numeric", vbExclamation, "Data Error"
: End If
: End Sub
:

[Rick Rothstein]

> If IsNumeric(txtAmtSold) Then

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 your 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 = 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

[J French]

On Mon, 27 Oct 2003 02:24:31 GMT, dfg <df*@dfg.net> wrote:

I do some error checking on my textbox. The problem is that if I enter
a valid number, then backspace until the box is empty, my msgbox pops up
saying "Data Error". Is there a way to avoid this?

Also, if I enter invalid data and try to backspace through it, my "Data
Error" msgbox pops up. This is rather annoying. Does anyone have a
solution to this problem? I posted my code - I hope it formats correctly.

Thanks. Gawd - the 'fix' solution is :-

Private Sub txtAmtSold_Change()
If txtAmtSold = "" Then
mnuEditCalculate.Enabled = False Exit Sub ' <==== GET OUT ==== End If

If IsNumeric(txtAmtSold) Then
If Val(txtAmtSold) >= 1 And Val(txtAmtSold) _
<= 100 Then
mnuEditCalculate.Enabled = True
Else
mnuEditCalculate.Enabled = False
MsgBox "Error: Numbers must be in the range of 1 - 100",
vbExclamation, "Range Error"
End If
Else
mnuEditCalculate.Enabled = False
MsgBox "Data Must Be Numeric", vbExclamation, "Data Error"
End If
End Sub

However, code like that is (IMO) completely unreadable.

Possibly because I am allergic to the use of 'Else'

In most cases 'Select Case' provides a clearer solution than messing
around with 'Else'

In this case heavy use of 'Exit Sub' would clear up your logic