Excel VBA轮询/防止代码在指定时间内运行多次

我有另一个在后台运行的代码，当满足某些条件时，它将调用子警报。虽然有多个场景调用此代码，但现在发生的是警报开始运行的频率高于我希望的3秒（由AlertTIMER指示）。下面是我解决这个问题的尝试

Sub Alert()
If Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton22.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
Beep
Application.Speech.Speak ("Part is done")
Beep
Call AlertTIMER
Exit Sub

ElseIf Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton22.Enabled = False Then
Beep
Application.Speech.Speak ("Part is done")
Beep
Call AlertTIMER
Exit Sub

ElseIf Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
Beep
Application.Speech.Speak ("Part is done")
Beep
Call AlertTIMER
Exit Sub

ElseIf Sheets("Sheet1").CommandButton22.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
Beep
Application.Speech.Speak ("Part is done")
Beep
Call AlertTIMER
Exit Sub

ElseIf Sheets("Sheet1").CommandButton21.Enabled = False Then
Beep
Application.Speech.Speak ("Part is done")
Beep
Call AlertTIMER
Exit Sub

ElseIf Sheets("Sheet1").CommandButton22.Enabled = False Then
Beep
Application.Speech.Speak ("Part is done")
Beep
Call AlertTIMER
Exit Sub

ElseIf Sheets("Sheet1").CommandButton25.Enabled = False Then
Beep
Application.Speech.Speak ("Part is done")
Beep
Call AlertTIMER
Exit Sub
Else
Exit Sub
End If

End Sub

Sub AlertTIMER()
Dim ACountDown As Date
ACountDown = Now + TimeValue("00:00:03")
Application.OnTime ACountDown, "Alert"
End Sub

很明显，这不起作用，哈哈。最初我有一个if语句，用or代替ands。。。但这也不起作用。有什么帮助吗

编辑：

我相信在AlertTIMER sub中发生了什么，它会计算一个倒计时值。在本例中，我们假设它首先在12:00:00 AM（A倒计时将=12:00:03 AM）触发，然后将其作为该值（12:00:03 AM）分包到Application.OnTime。当触发另一个事件时，比如说在12:00:01 AM，它将计算一个倒数为12:00:04 AM，然后将其作为该值（12:00:04 AM）提交给Application.OnTime。最后我在12:00:03和12:00:04触发了“警报”。解决这一问题的一种方法是，如果代码将计数作为一个变量保留，直到从Application.OnTime触发“警报”？？。因此，在上一个示例中，它首先计算12:00:03 AM进行倒计时，然后在第二个触发器进入时重置为12:00:04 AM。在凌晨12:00:04，它通过Application.OnTime触发“警报”-只运行一次

编辑2：

另一种解决方法是，如果有办法做到这一点，可以检查是否有Application.OnTime正在运行/处于活动状态，如果是，则取消它。代码如下所示：

Sub AlertTIMER()
Dim ACountDown As Date

If Application.OnTime(, "Alert") Is Nothing Then
Else
 Application.OnTime ACountDown, "Alert", , False
End If

ACountDown = Now + TimeValue("00:00:03")
Application.OnTime ACountDown, "Alert"
End Sub

Sub Alert()

    If Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton22.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton22.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton22.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton21.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton22.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton25.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep
    Else
        Exit Sub
    End If

    Call AlertTIMER

End Sub

但是

如果Application.OnTime（，“Alert”）为空，则
返回一个错误。。。因为它不是一个对象，所以你不能检查它是否为空。有没有想过我该如何让它发挥作用？
试着这样做：

Sub AlertTIMER()
Dim ACountDown As Date

If Application.OnTime(, "Alert") Is Nothing Then
Else
 Application.OnTime ACountDown, "Alert", , False
End If

ACountDown = Now + TimeValue("00:00:03")
Application.OnTime ACountDown, "Alert"
End Sub

Sub Alert()

    If Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton22.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton22.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton21.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton22.Enabled = False And Sheets("Sheet1").CommandButton25.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton21.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton22.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep

    ElseIf Sheets("Sheet1").CommandButton25.Enabled = False Then
        Beep
        Application.Speech.Speak ("Part is done")
        Beep
    Else
        Exit Sub
    End If

    Call AlertTIMER

End Sub

这不完全是我想要的，但我想它完成了工作。。。这允许“嘟嘟，部分完成，嘟嘟”同步，而不是竞争。如果AlertTimer在之前已被触发（等待CurrTick到达EndTick）的情况下被触发，则EndTick将被重置，因此现在它只被触发一次。
“它不工作”不会告诉我们任何信息。告诉我们实际发生了什么，应该发生什么。举个例子也很有帮助。我知道我没有举个例子。。。至于代码，但我试图解释它：“现在发生的是警报开始运行的频率比我希望的3秒要高”换句话说，当警报在另一个代码中多次触发时，而不是听到“嘟嘟*，部分完成，嘟嘟*”等待3秒“嘟嘟*，部分完成，嘟嘟*”。。。我听到“嘟嘟*，部分完成，嘟嘟*”等待（随机秒数小于3）“嘟嘟*，部分完成，嘟嘟*”。谢谢，我相信我试过了，但它不起作用，但我会再试一次，让你知道。我现在手头没有代码。这不起作用，如果两个事件触发，那么“嘟嘟，部分完成，嘟嘟”竞争。