VBA EventHandler firing twice? - vba

Question

I have MS Access 2003 DB.
Is it possible for an event handler for a button on a form to fire twice??
I seem to have evidence of this happening as I have a payroll process
that logs the whole process and process is duplicated in the log.
I didnt think this was possible in VBA???
EDIT:
I discovered that indeed it was firing twice as user was clicking twice and queueing the event twice.
This is the fix I made to the code which shows using a flag m_locked as an example to test with:
[code]
Private m_locked As Boolean
Private m_count As Integer
Private Sub Command0_Click()
On Error GoTo Err_Command0_Click
' wait
If Not m_locked Then
m_locked = True
Dim startTime As Date
startTime = Now()
While DateDiff("s", startTime, Now()) < 3
DoEvents
Wend
' increment counter
m_count = m_count + 1
Command0.Caption = m_count
m_locked = False
End If
Exit_Command0_Click:
Exit Sub
Err_Command0_Click:
MsgBox Err.Description
Resume Exit_Command0_Click
End Sub
[/code]
Malcolm

Answer 1

Seeing your "solution" I'ld recommend to specify the double click event, too. This will allow you to distinguish easily whether the user clicked once or twice by a "debug.print".
To prevent the user to perform an extra click, declare a private boolean variable on form module level, set it to TRUE in your event procedure, set it to FALSE in the timer event, and configure your form's timer to 1000 for example (it's milliseconds).
Option Explicit
Option Compare Database
Private oneClick As Boolean
Private Sub cmdMyButton_Click()
If not oneClick Then
' Perform your actions here
End If
oneClick = True
End Sub
Private Sub Form_Timer()
oneClick = False
End Sub
Oh, and please use variable and control names that tell their meaning :-)

Answer 2

If you do not want your user click the button twice just this simple code:
Private Sub Command0_Click()
Command0.Enabled = False
' Continue with your code here ...
End Sub