Forms GotFocus event does not seem to fire

I'm try开发者_如何学Going to call an event when the user returns focus to the Access application when a specific form is open. The following event doesn't seem to fire up at all.

Private Sub Form_GotFocus()
    Call crtListDirectory
End Sub 

Does any body have any ideas as to how I could trigger this event to happen, and when/how does the Form_GotFocus event actually get triggered.

thanks in advance for any help

Noel

---

Access help:

A form can get the focus only if all visible controls on a form are disabled, or there are no controls on the form.

You might like to try Activate.

EDIT re Comments

The only way I can see of doing what you seem to want is with APIs, which is somewhat messy. To demonstrate this you will need a form with two controls Text0 and Text2 (these are the default names). Set the Timer Interval to something suitable, say 2000, and the Timer Event to:

Private Sub Form_Timer()
Dim lngWin As Long
Dim s As String

    'This is just a counter to show that the code is running
    Me.Text2 = Nz(Me.Text2, 0) + 1

    'API
    lngWin = GetActiveWindow()
    s = GetWinName(lngWin)

    If s = "Microsoft Access" Then
        If Me.Text0 = "Lost Focus" Then
            Me.Text0 = "Focus returned"
        End If
    Else
        Me.Text0 = "Lost Focus"
    End If

End Sub

You will now need a module for:

Option Compare Database

Declare Function GetActiveWindow Lib "user32" () As Integer
Declare Function GetWindowText Lib "user32.dll" Alias _
"GetWindowTextA" (ByVal hwnd As Long, ByVal lpString As _
String, ByVal cch As Long) As Long
Declare Function GetWindowTextLength Lib "user32" Alias _
"GetWindowTextLengthA" (ByVal hwnd As Long) As Long

Function GetWinName(hw As Long)
    Dim lngText As Long ' receives length of text of title bar
    Dim strWinName As String ' receives the text of the title bar
    Dim lngWinText As Long ' receives the length of the returned string

    lngText = GetWindowTextLength(hw)
    strWinName = Space(lngText + 1)
    lngWinText = GetWindowText(hw, strWinName, lngText + 1)
    strWinName = Left(strWinName, lngWinText)
    GetWinName = strWinName
End Function

This is all very, very rough, but it gives you something to mess about with.