trouble setting a max and min value

I have the following code:

Private Sub numericTextboxKeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
Dim tb As TextBox = CType(sender, TextBox)
Dim chr As Char = e.KeyChar
If IsNumeric(e.KeyChar) And Not e.KeyChar = "-" Then
'If adding the character to the end of the current TextBox value results in
' a numeric value, go on. Otherwise, set e.Handled to True, and don't let
' the character to be added.
e.Handled = Not IsNumeric(tb.Text & e.KeyChar)
ElseIf Not Char.IsControl(e.KeyChar) Then
'IsControl is checked, because without that, keys like BackSpace couldn't
' work correctly.
e.Handled = True
My.Computer.Audio.PlaySystemSound(Media.SystemSounds.Beep)
End If
End Sub

This allows only numeric characters to be entered into the textbox. I just cannot figure out a way to limit the maximum value and the minimum value for the value in the textbox.

Say I want the maximum value to be 237 and the minimum value to be 36. If the value is above that then it is reset to the maximum value. Or if it is below the minimum then it is reset to the minimum value. How would I do this. Also, I am trying not to use a numericupdown controls, so don't bother posting that suggestion.

Thank you in advance for any help that is provided.

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trouble setting a max and min value

blucas2006

Hi Troy,

You can use Regx to validate the input.
adman666
This is what I use:

Private Sub checkValue(ByVal sender As Object, ByVal e As System.EventArgs)
Dim tb As TextBox = CType(sender, TextBox)
Dim min As Byte = 0
Dim max As Byte = 255
If sender.Equals(tb2) OrElse sender.Equals(tb4) Then
min = 1
max = 16
End If
If tb.Text = String.Empty Then Exit Sub
If CDbl(tb.Text) < min Then tb.Text = CStr(min)
If CDbl(tb.Text) > max Then tb.Text = CStr(max)
End Sub

It works perfect. Also, if the value is blank then it exits instead of throwing an exception. It also handles cases where the min and max values would be different.
Simone Poste
Hi Joe Smugeresky ,

It is very wrong to hard code the values.
Kuba B
Please give an example of how you would code it.
Gimpy

Not sure how your workflow is but you could use the Leave event:

Private Sub TextBox1_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Leave

Dim value As Integer = Convert.ToInt32(TextBox1.Text)

If value < 36 Then
TextBox1.Text = "36"
ElseIf value > 237 Then
TextBox1.Text = "237"
End If

End Sub

-Joe
Sambuddha

Hi,

try this link and tell me if that helps.

http://www.c-sharpcorner.com/Language/RegExpressionSample1.asp

Regards,
shanytopper
Yes, i could be good for you, however this code is hardcoded with all the ifs and consts. You might think to refactor it and use Regx.
CRickert
It was a sample, hardly production code. Samples are meant to be easy to understand, hence the hard coded values.
trouble setting a max and min value

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