Home » Tip Bank » Application Design » User Interface Design

Language: VB
Expertise: Intermediate

Jan 12, 2004

First, place the function ischaralpha in the proyect. In this example it's in the general declarations section of the form:

Private Declare Function IsCharAlpha Lib "user32" Alias "IsCharAlphaA"
(ByVal cChar As Byte) As Long

Next, place a textbox in the form. Then, copy the next code to limit the user entry only to alphabetic characters:

If KeyAscii = vbKeyBack Or KeyAscii = vbKeySpace Then
KeyAscii = KeyAscii
Exit Sub
End If

num = IsCharAlpha(KeyAscii)
If num = 0 Then
KeyAscii = 0
End If

With some changes in the code, you can limit the user entry to only numbers:

permitir solo numeros
If KeyAscii = vbKeyBack Or KeyAscii = vbKeySpace Then
KeyAscii = KeyAscii
Exit Sub
End If

Select Case Chr(KeyAscii)
Case "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
KeyAscii = KeyAscii
Case Else
KeyAscii = 0
End Select