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Timing Delays in VBA

开发者 https://www.devze.com 2023-03-26 09:47 出处:网络
I would like a 1 second delay in my code.Below is the code I am trying to make this delay.I think it polls the date and time off the operating system and waits until the times match.I am having an iss

I would like a 1 second delay in my code. Below is the code I am trying to make this delay. I think it polls the date and time off the operating system and waits until the times match. I am having an issue with the delay. I think it does not poll the time when it matches the wait time and it just sits there and freezes up. It only freezes up about 5% of the time I run the code. I was wondering about Application.Wait and if there is a way to check if the polled time is greater than the wait tim开发者_StackOverflowe.

   newHour = Hour(Now())
   newMinute = Minute(Now())
   newSecond = Second(Now()) + 1
   waitTime = TimeSerial(newHour, newMinute, newSecond)
   Application.Wait waitTime


If you are in Excel VBA you can use the following.

Application.Wait(Now + TimeValue("0:00:01"))

(The time string should look like H:MM:SS.)


I use this little function for VBA.

Public Function Pause(NumberOfSeconds As Variant)
    On Error GoTo Error_GoTo

    Dim PauseTime As Variant
    Dim Start As Variant
    Dim Elapsed As Variant

    PauseTime = NumberOfSeconds
    Start = Timer
    Elapsed = 0
    Do While Timer < Start + PauseTime
        Elapsed = Elapsed + 1
        If Timer = 0 Then
            ' Crossing midnight
            PauseTime = PauseTime - Elapsed
            Start = 0
            Elapsed = 0
        End If
        DoEvents
    Loop

Exit_GoTo:
    On Error GoTo 0
    Exit Function
Error_GoTo:
    Debug.Print Err.Number, Err.Description, Erl
    GoTo Exit_GoTo
End Function


You can copy this in a module:

Sub WaitFor(NumOfSeconds As Long)
Dim SngSec as Long
SngSec=Timer + NumOfSeconds

Do while timer < sngsec
DoEvents
Loop

End sub

and whenever you want to apply the pause write:

Call WaitFor(1)

I hope that helps!


Have you tried to use Sleep?

There's an example HERE (copied below):

Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Sub Form_Activate()    

frmSplash.Show
DoEvents
Sleep 1000
Unload Me
frmProfiles.Show

End Sub

Notice it might freeze the application for the chosen amount of time.


Access can always use the Excel procedure as long as the project has the Microsoft Excel XX.X object reference included:

Call Excel.Application.Wait(DateAdd("s",10,Now()))


Your code only creates a time without a date. If your assumption is correct that when it runs the application.wait the time actually already reached that time it will wait for 24 hours exactly. I also worry a bit about calling now() multiple times (could be different?) I would change the code to

 application.wait DateAdd("s", 1, Now)


Another variant of Steve Mallorys answer, I specifically needed excel to run off and do stuff while waiting and 1 second was too long.

'Wait for the specified number of milliseconds while processing the message pump
'This allows excel to catch up on background operations
Sub WaitFor(milliseconds As Single)

    Dim finish As Single
    Dim days As Integer

    'Timer is the number of seconds since midnight (as a single)
    finish = Timer + (milliseconds / 1000)
    'If we are near midnight (or specify a very long time!) then finish could be
    'greater than the maximum possible value of timer. Bring it down to sensible
    'levels and count the number of midnights
    While finish >= 86400
        finish = finish - 86400
        days = days + 1
    Wend

    Dim lastTime As Single
    lastTime = Timer

    'When we are on the correct day and the time is after the finish we can leave
    While days >= 0 And Timer < finish
        DoEvents
        'Timer should be always increasing except when it rolls over midnight
        'if it shrunk we've gone back in time or we're on a new day
        If Timer < lastTime Then
            days = days - 1
        End If
        lastTime = Timer
    Wend

End Sub


The Timer function also applies to Access 2007, Access 2010, Access 2013, Access 2016, Access 2007 Developer, Access 2010 Developer, Access 2013 Developer. Insert this code to to pause time for certain amount of seconds

T0 = Timer
Do
    Delay = Timer - T0
Loop Until Delay = 1 'Change this value to pause time in second


The handling of midnight in the accepted answer is wrong. It tests for Timer = 0, which will almost never happen. It should instead test for Timer < Start. Another answer tried a correction of Timer >= 86399, but that test can also fail on a slow computer.

The code below handles midnight correctly (with a bit more complexity than Timer < Start). It also is a sub, not a function, because it doesn't return a value, and variables are singles because there is no need for them to be variants.

Public Sub pPause(nPauseTime As Single)

' Pause for nPauseTime seconds.

Dim nStartTime As Single, nEndTime As Single, _
    nNowTime As Single, nElapsedTime As Single

nStartTime = Timer()
nEndTime = nStartTime + nPauseTime

Do While nNowTime < nEndTime
    nNowTime = Timer()
    If (nNowTime < nStartTime) Then     ' Crossed midnight.
        nEndTime = nEndTime - nElapsedTime
        nStartTime = 0
      End If
    nElapsedTime = nNowTime - nStartTime
    DoEvents    ' Yield to other processes.
  Loop

End Sub


I used the answer of Steve Mallory, but I am affraid the timer never or at least sometimes does not go to 86400 nor 0 (zero) sharp (MS Access 2013). So I modified the code. I changed the midnight condition to "If Timer >= 86399 Then" and added the break of the loop "Exit Do" as follows:

Public Function Pause(NumberOfSeconds As Variant)
    On Error GoTo Error_GoTo

    Dim PauseTime As Variant
    Dim Start As Variant
    Dim Elapsed As Variant

    PauseTime = NumberOfSeconds
    Start = Timer
    Elapsed = 0
    Do While Timer < Start + PauseTime
        Elapsed = Elapsed + 1
        If Timer >= 86399
            ' Crossing midnight
            ' PauseTime = PauseTime - Elapsed
            ' Start = 0
            ' Elapsed = 0
            Exit Do
        End If
        DoEvents
    Loop

Exit_GoTo:
    On Error GoTo 0
    Exit Function
Error_GoTo:
    Debug.Print Err.Number, Err.Description, Erl
    GoTo Exit_GoTo
End Function


On Windows timer returns hundredths of a second... Most people just use seconds because on the Macintosh platform timer returns whole numbers.


With Due credits and thanks to Steve Mallroy.

I had midnight issues in Word and the below code worked for me

Public Function Pause(NumberOfSeconds As Variant)
 '   On Error GoTo Error_GoTo

    Dim PauseTime, Start
    Dim objWord As Word.Document

    'PauseTime = 10 ' Set duration in seconds
    PauseTime = NumberOfSeconds
    Start = Timer ' Set start time.

    If Start + PauseTime > 86399 Then 'playing safe hence 86399

    Start = 0

    Do While Timer > 1
        DoEvents ' Yield to other processes.
    Loop

    End If

    Do While Timer < Start + PauseTime
        DoEvents ' Yield to other processes.
    Loop

End Function


For MS Access: Launch a hidden form with Me.TimerInterval set and a Form_Timer event handler. Put your to-be-delayed code in the Form_Timer routine - exiting the routine after each execution.

E.g.:

Private Sub Form_Load()
    Me.TimerInterval = 30000 ' 30 sec
End Sub

Private Sub Form_Timer()

    Dim lngTimerInterval  As Long: lngTimerInterval = Me.TimerInterval

    Me.TimerInterval = 0

    '<Your Code goes here>

    Me.TimerInterval = lngTimerInterval
End Sub

"Your Code goes here" will be executed 30 seconds after the form is opened and 30 seconds after each subsequent execution.

Close the hidden form when done.

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