Checking for Alpha

[Dooglo]

How do I check to see if my textbox has a alpha character in it?

I don't want alpha characters, numeric only.

Thanks

Dooglo

[Cor Ligthert]

Dooglo,

What is alpha in this case, latin alphabeth 26 characters like in the
english/dutch and maybe somemore languages or more characters?

Cor

[Greg Burns]

Here is one way using a reqex expression:

Private Sub txtMyTextbox_Va lidating(ByVal sender As Object, ByVal e As
System.Componen tModel.CancelEv entArgs) Handles txtMyTextbox.Va lidating
Validate_txtMyT extbox()
End Sub

Private Sub Validate_txtMyT extbox()
If txtUsedYTD.Text = String.Empty Then
ErrorProvider1. SetError(txtMyT extbox, "Required")
_error = True
ElseIf Not IsNumeric(txtMy Textbox.Text) Then
ErrorProvider1. SetError(txtMyT extbox, "Not valid")
_error = True
Else
' is it really a number?

Dim rNumber As New
System.Text.Reg ularExpressions .Regex("(^\d*\. ?\d*[0-9]+\d*$)|(^[0-9]+\d*\.\d
*$)")
If rNumber.IsMatch (txtMyTextbox.T ext) Then
ErrorProvider1. SetError(txtMyT extbox, "")
Else
ErrorProvider1. SetError(txtMyT extbox, "Not valid")
_error = True
End If
End If
End Sub

HTH,
Greg

"Dooglo" <Do****@discuss ions.microsoft. com> wrote in message
news:81******** *************** ***********@mic rosoft.com...

How do I check to see if my textbox has a alpha character in it?

I don't want alpha characters, numeric only.

Thanks

Dooglo

[Henrik]

Hi Doogle,

You can check it while the user types it:

Private Sub TextBox1_TextCh anged(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles TextBox1.TextCh anged

If Char.IsLetter(C Char(TextBox1.T ext)) = True Then

End If

End Sub

-or chec
http://msdn.microsoft.com/library/de...ettertopic.asp
/Henrik

"Dooglo" wrote:

How do I check to see if my textbox has a alpha character in it?

I don't want alpha characters, numeric only.

Thanks

Dooglo

[VJ]

If you meant, I need only 0-9 and no other characters... you can use Regular
Expressions..

Imports System.Text.Reg ularExpressions

Private Function ValidateString( ByVal strText as string) as boolean

Dim retVal as boolean

retVal = RegEx.IsMatch(s trText,"[0-9]")

return retVal

End Function

For more regEx expressions see... www.regexlib.com

VJ

"Dooglo" <Do****@discuss ions.microsoft. com> wrote in message
news:81******** *************** ***********@mic rosoft.com...

How do I check to see if my textbox has a alpha character in it?

I don't want alpha characters, numeric only.

Thanks

Dooglo

[Herfried K. Wagner [MVP]]

* =?Utf-8?B?RG9vZ2xv?= <Do****@discuss ions.microsoft. com> scripsit:

How do I check to see if my textbox has a alpha character in it?

I don't want alpha characters, numeric only.

I would not prevent the user from entering these characters, instead I
would validate input in the textbox's 'Validating' event and make the
user aware of malformed input using an error provider. For example:

\\\
Private Sub TextBox1_Valida ting( _
ByVal sender As Object, _
ByVal e As CancelEventArgs _
) Handles TextBox1.Valida ting
Dim SourceControl As TextBox = DirectCast(send er, TextBox)
Try
Dim i As Integer = Integer.Parse(S ourceControl.Te xt)
If Me.ErrorProvide r1.GetError(Sou rceControl).Len gth > 0 Then
Me.ErrorProvide r1.SetError(Sou rceControl, "")
End If
Catch ex As Exception
Me.ErrorProvide r1.SetError( _
SourceControl, "Value must be an integer." & ex.Message & ")" _
)
End Try
End Sub
///

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Cor Ligthert]

Misreaded,

So because everybody who visitst this newsgroup have to give a solution
\\\only figures limited to 10 as plus as well as minus is possible as well
as exponents

Private Sub Form1_Load(ByVa l sender As System.Object, _
ByVal e As System.EventArg s) Handles MyBase.Load
Me.TextBox1.Max Length = 10
End Sub
Private Sub textbox1_KeyUp( ByVal sender As Object, _
ByVal e As System.Windows. Forms.KeyEventA rgs) Handles textbox1.KeyUp
If e.KeyValue <> 8 Then
If Not IsNumeric(TextB ox1.Text) Then
If TextBox1.Text.L ength > 0 Then
MessageBox.Show ("Only numeric is allowed")

TextBox1.Select ionStart = TextBox1.Text.L ength - 1
TextBox1.Select ionLength = 1
End If

End If
End If
End Sub
Private Sub TextBox1_Valida ting(ByVal sender _
As Object, ByVal e As System.Componen tModel.CancelEv entArgs) _
Handles TextBox1.Valida ting
If TextBox1.Text.L ength > 0 Then
If Not IsNumeric(TextB ox1.Text) Then
MessageBox.Show ("There was an error pasting")
TextBox1.Focus( )
e.Cancel = True
End If
End If
End Sub
I hope this helps a little bit?

Cor

[Cor Ligthert]

Dooglo,

Forgot this question. I was to much looking at the subject

Cor

[Dooglo]

Thanks everyone for replying.

All examples are great!

"Dooglo" wrote:

How do I check to see if my textbox has a alpha character in it?

I don't want alpha characters, numeric only.

Thanks

Dooglo