Prevent user keying by keyboard and can only input by barcode scanner

[alvintiow]

Hi,

I intend to use barcode for input and prevent user to modify the barcode they scan, user are not allow to input the barcode number by keyboard.



Please advise how to do this.

Thanks.

Regards,
Alvin

[Stewart Ross]

Hi. Most barcode scanners for PCs use the keyboard connection, and the scan behaves just as if you had typed the value. I can see no way to prevent users either keying the barcode directly, or altering it once a barcode has been scanned.

Even if you could implement such a facility, you would also be stopping users from manually keying barcodes if the scan fails for some reason.

-Stewart

[missinglinq]

Stewart raises a valid point, but if you absolutely must do this , this code will do the job:

Private Sub txtBarCode_KeyDown(KeyCode As Integer, Shift As Integer)
  KeyCode = 0
End Sub

Or you could simply set the textbox's Locked Property to Yes. I don't have a scanner, so I can't really test this, but both methods appear to handle your situation.

Welcome to Bytes!

Linq ;0)>

[Delerna]

I have done both of those for the purpose of obtaining part labels.
Stop the user entering maually similar to missinglig's code.
Stopped production getting labels because the scanner failed.

We finished up enabling users to manually enter part numbers, but we deliberately made it more difficult to obtain them that way than by using the scanner. It worked :)

Edit
Actually, on second thoughts, I think I may have had to wrap the barcoded number up in special characters and check the entered number for the presence of those characters before allowing the entry.

[IAMREALITY]

This is how I solved it:

Public FirstInput As Date
 
Private Sub Text0_GotFocus()
FirstInput = Empty
End Sub
 
 
Private Sub Text0_KeyUp(KeyCode As Integer, Shift As Integer)
Dim TimeDiff As Integer
'Procedure uses first keystroke to start timing, and every subsequent keystroke compares
'to the first, and if more than 1 second has elapsed, warns user to use the scanner and resets field.
'tabbing away or back to the field resets the timer. Tabbing off the field or hitting enter to move to
'the next field will not be counted as keystrokes.
 
If KeyCode <> 9 And KeyCode <> 13 Then
If FirstInput = Empty Then
FirstInput = Now()
Else
TimeDiff = DateDiff("s", FirstInput, Now())
End If
 
If TimeDiff > 1 Then
MsgBox ("Please scan in using the attached scanner")
Text0.Text = Empty
FirstInput = Empty
End If
 
End If
 
End Sub
 
Private Sub Text0_LostFocus()
FirstInput = Empty
End Sub
 

[ADezii]

You can actually disable all User Input via the Mouse and Keyboard then re-enable it via the API, but this may be somewhat extreme.