ms-access - Forms GotFocus 事件似乎没有触发

Question

当特定表单打开时，当用户将焦点返回到 Access 应用程序时，我试图调用一个事件。以下事件似乎根本没有发生。

Private Sub Form_GotFocus()
    Call crtListDirectory
End Sub 

是否有人对我如何触发此事件以及 Form_GotFocus 事件何时/如何实际触发有任何想法。

提前感谢您的帮助

诺埃尔

Answer 1

Access 帮助:

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

您可能想尝试激活。

编辑重新评论

我能看到做你想做的事情的唯一方法是使用 API，这有点困惑。为了演示这一点，您将需要一个带有两个控件 Text0 和 Text2(这些是默认名称)的表单。将 Timer Interval 设置为合适的值，例如 2000，并将 Timer Event 设置为:

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

您现在需要一个模块:

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

这一切都非常非常粗糙，但它会给你一些麻烦。