Restrict what characters can be entered into all textBoxes on a form

This is for beginners who have multiple Textboxes and want to restrict the type of characters that can be entered in to each of them.
I wanted this for my project and looked around but could only find examples of restricting numbers to one textbox, which would have meant a lot of repetitive code
i.e TextBox1 only numbers, TextBox2 only Numbers, TextBox3 only Numbers etc

The code below only allows Numbers and the backspace to be entered.
In form Load event

Code:

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        'Add key press event for each textbox
        For Each tb In Me.Controls.OfType(Of TextBox)()
            AddHandler tb.KeyPress, AddressOf keypressed
        Next

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in the body of the code

Code:

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    Private Sub keypressed(ByVal o As [Object], ByVal e As KeyPressEventArgs)
        'Only allow numbers and backspace to be entered in any of the textboxes
        If Asc(e.KeyChar) <> 8 AndAlso Not IsNumeric(e.KeyChar) Then
            MessageBox.Show("Only numbers 0 - 9 and the backspace can be entered")
            e.Handled = True
        End If
    End Sub

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vb.net Code:

If Asc(e.KeyChar) <> 8 AndAlso Not IsNumeric(e.KeyChar) Then

Ooh, no no no.

vb.net Code:

If Not (Char.IsDigit(e.KeyChar) OrElse Char.IsControl(e.KeyChar)) Then

Char.IsControl will allow Delete and other control characters as well as Backspace, but any that the user can enter should be allowed anyway.

Quote:

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Ooh, no no no.

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:D
Just when I think I'm being helpful!
At least any beginners can read both post or the mods can delete it. Whichever

Quote:

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Originally Posted by Mallard8

Just when I think I'm being helpful!

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You were, so there was nothing wrong with posting. Plenty of my CodeBank posts, as well as other posts, could almost certainly be improved upon. That especially goes for those I wrote when I had less experience than I do now.

Thing is john when I removed my line of code and replaced it with yours I was able to place letters in the textbox?
So have I misunderstood what you are trying to show in the code you posted?

I think the AndAlso should have been OrElse

...or to arguably make it more readable, use two Not's instead:

Code:

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    If Not (Char.IsDigit(e.KeyChar)) AndAlso Not (Char.IsControl(e.KeyChar)) Then

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Quote:

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Originally Posted by si_the_geek

I think the AndAlso should have been OrElse

...or to arguably make it more readable, use two Not's instead:

Code:

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    If Not (Char.IsDigit(e.KeyChar)) AndAlso Not (Char.IsControl(e.KeyChar)) Then

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You're correct. I started out with that and then edited it but forgot to change the AndAlso to OrElse. I've edited my original post.

When I can take the stone from the hand of the master my training will be complete. :rolleyes: