how to use validation in visual basic

[anianu]

i want to know how to do validation in visual basic.means how to avoid entering numbers in textbox where we need only characters and also opposite means how to avoid characters where we only need numeric

plz reply me soon..
thanks in advance .
i m waiting 4 ur reply

[bartonc]

Sorry, I inadvertently moved one of your posts to the Misc. Q.s Forum from Member Introductions.
My mistake, but could be avoided it you post in the relevant forum.

Hope you are finding your way around the site by now.

[Killer42]

i want to know how to do validation in visual basic.means how to avoid entering numbers in textbox where we need only characters and also opposite means how to avoid characters where we only need numeric

Three techniques initially come to mind...

• In the KeyPress, KeyDown or Change event, discard unwanted characters.
• Use a masked edit control instead of a textbox. The masked edit control lets you specify the format that it will accept form the user.
• Just check the value when the user leaves the textbox. You can do this in the LostFocus event, but the Validate event is probably more appropriate.

Note, all of this relates to VB6. You didn't say what version you're using, but if it's a later version the details may vary, though the general idea would be the same.

[anianu]

i want to know how to do validation in visual basic.means how to avoid entering numbers in textbox where we need only characters and also opposite means how to avoid characters where we only need numeric

plz reply me soon..
thanks in advance .
i m waiting 4 ur reply

Sorry, I inadvertently moved one of your posts to the Misc. Q.s Forum from Member Introductions.
My mistake, but could be avoided it you post in the relevant forum.

Hope you are finding your way around the site by now.

[hariharanmca]

i want to know how to do validation in visual basic.means how to avoid entering numbers in textbox where we need only characters and also opposite means how to avoid characters where we only need numeric

plz reply me soon..
thanks in advance .
i m waiting 4 ur reply

Public Function NumberOnly(KeyAscii As Integer, TxtInput As String) As Integer
    Dim loopx As Integer
    If KeyAscii = 8 Or (KeyAscii >= 48 And KeyAscii <= 57) Then
        NumberOnly = KeyAscii
        Exit Function
    End If
    If KeyAscii = 46 Then
        For loopx = 1 To Len(TxtInput)
            If Asc(Mid(TxtInput, loopx, 1)) = 46 Then
                NumberOnly = 0
                Exit Function
            End If
        Next
        NumberOnly = KeyAscii
        Exit Function
    End If
    NumberOnly = 0
End Function
 

the above method will return keysscii value
1. if txtString is contain only number
2. if txtString is contain only one '.'(Dot-Decimal place)


(Killer indicate you to try some thing but you never).

[hariharanmca]

Public Function NumberOnly(KeyAscii As Integer, TxtInput As String) As Integer
    Dim loopx As Integer
    If KeyAscii = 8 Or (KeyAscii >= 48 And KeyAscii <= 57) Then
        NumberOnly = KeyAscii
        Exit Function
    End If
    If KeyAscii = 46 Then
        For loopx = 1 To Len(TxtInput)
            If Asc(Mid(TxtInput, loopx, 1)) = 46 Then
                NumberOnly = 0
                Exit Function
            End If
        Next
        NumberOnly = KeyAscii
        Exit Function
    End If
    NumberOnly = 0
End Function
 

the above method will return keysscii value
1. if txtString is contain only number
2. if txtString is contain only one '.'(Dot-Decimal place)


(Killer indicate you to try some thing but you never).

for this

If Asc(Mid(TxtInput, loopx, 1)) = 46 Then

you can also use

If InStr(1, Trim(TxtInput), ".") > 0 Then

without any for loop