Disable Keys

Hi friends,

I am new to VB.just now started to coding . I am designing one application in that one text box should allow only (A-Z,0-9,/).when other keys pressed it wont work i.e., i have to lock when other key pressed.

please guide me and give logic/code to complete above task.

Try this

vb Code:

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
 
        Select Case e.KeyChar
            Case "A" To "Z"
                ' do nothing
            Case "0" To "9"
                ' do nothing
            Case "\"
                ' do nothing
            Case Else
                ' suspend other keys
                e.KeyChar = ""
        End Select
 
    End Sub

@ecalt:

What version of Visual Basic do you use?

Quote:

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Originally Posted by 4x2y

Try this

vb Code:

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
 
        Select Case e.KeyChar
            Case "A" To "Z"
                ' do nothing
            Case "0" To "9"
                ' do nothing
            Case "\"
                ' do nothing
            Case Else
                ' suspend other keys
                e.KeyChar = ""
        End Select
 
    End Sub

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That's not even needed, the only method you'd need to use is:

Code:

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e.SupressKeypress

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That's it.

Quote:

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Originally Posted by AceInfinity

That's not even needed, the only method you'd need to use is:

Code:

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e.SupressKeypress

---

That's it.

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There must be some checks because not all keys need to suspended.

I have used e.KeyChar = "" because e.SupressKeypress is available only under KeyUp/Down events.

Quote:

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Originally Posted by 4x2y

There must be some checks because not all keys need to suspended.

I have used e.KeyChar = "" because e.SupressKeypress is available only under KeyUp/Down events.

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That's true, I wasn't referring to his exact code in that statement though, but with your code, I would do something like this, which is a bit more efficient:

Code:

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Dim MyChars As String = "/" & vbBack
e.Handled = Not Char.IsLetterOrDigit(e.KeyChar) AndAlso MyChars.IndexOf(e.KeyChar) = -1

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The way you have it set up now, it won't accept input if the char value is lowercase, only uppercase.

Why is this thread in the API forum? It really belongs in VB.Net.

This is .net code

The guy asked for API. If you can't give him an API solution, your solution probably isn't wanted. Most people in the API forum have VB6, but want to do the cool things of .net so they use API to get most similar functions.