Cannot interrupt running operation in vba when command button is being pressed - vba

I researched net, but I haven`t found a solution yet and I am still grappling with the following problem:
In vba UserForm I have two command buttons:
1st one ('Run Operation') runs an operation that could take around 30 minutes.
2nd one ('Cancel') was created to interrupt the operation that was triggered off by 'Run Operation'
When I press 'Run Operation' button I cannot press neither 'Cancel' nor 'x' to stop the running operation and I have to wait until the operation finishes, thus the userform is freezed for around 30 minutes.
Code looks more or less like this:
private Sub Cancel_Click()
Cancel = True
End Sub
private Sub RunOperation_Click()
RunOperation.Enabled = False
Call Macro()
End Sub
private Sub Macro()
For i = 1 to 100
'do stuff here
If Cancel = True Then
RunOperation.Enabled = True
Exit Sub
Exit If
Next i
End Sub
What`s more both buttons have TakeFocusOnClick set to False.
I`d be grateful for any ideas.
Thanks in advance !

The DoEvents method is your friend here.
What's happening is that since VBA is single-threaded (i.e. only one macro can be running at a time) it's not possible for events (in your case Cancel_Click()) to trigger. The DoEvents method essentially pauses the code wherever it appears to see if any other events have been triggered and resolves them before code execution is resumed.
Try this, it should work:
Private Sub Macro()
For i = 1 To 100
'do stuff here
DoEvents '<~~ Insert this line here
If Cancel = True Then
RunOperation.Enabled = True
Exit Sub
End If
Next i
End Sub

Related

VBA - UserForm Button (Macro) to Continue running the sub

I have a sub called as sub1() which activates the userform1 through the command userform1.show()
This userform1 has a button called as continue. On clicking that button continue - A Macro called as Private Sub continuebutton() gets activated.
I want to program in such a way that it redirects to the line after userform1.show() in sub1().
Is it something that can be done?
Theoretically, what you want is possible, if you do it like this:
In the UserForm:
Private Sub btnContinue_Click()
flag = True
Debug.Print "I continue ..."
sub1
End Sub
In a module:
Public flag As Boolean
Public Sub sub1()
If flag Then
Debug.Print "sub 1 continues here..."
Else
flag = False
UserForm1.Show
Exit Sub
End If
End Sub
It will work exactly as intended, BUT it is not a good practice to work this way. (Some people may throw stones at you for using public variables at all in VBA.) Here are two articles, that give better ideas:
https://rubberduckvba.wordpress.com/2017/10/25/userform1-show/
Disclaimer - this one is mine:
http://www.vitoshacademy.com/vba-the-perfect-userform-in-vba/
On the form properties for userform1, set its "Modal" property to true.
When the form opens, it will have exclusive focus, and the code in sub1 will not continue running until after it closes. This may be the solution you need.
In the code below, the msgbox will only appear once userform1 closes:
sub sub1()
userform1.show()
msgbox "Now continuing with sub1"
end sub
No way as long as you show the form.
If you show the form modal, the calling routine continues if (and only if) the form is closed.
If you show the form non-modal, the code continues to run directly after the show - so it's already done.
So either you have to close the form when the user clicks the "continue..." button to let the calling macro continue or you have to split your code into two routines and call the second on button-click.
You can change your Sub1 as follows:
Sub sub1(Optional Continue As Boolean)
If Continue = True Then
DoSomeStuff
Exit Sub
End If
userform1.show
End sub
And then, you can call your sub1 using:
Private Sub continuebutton()
Call sub1(True)
End Sub
Hope it helps
If you don't want to go with the 'Modal Form' solution, you could add a subroutine to your main module, and call it when required. So, in userform1, you have:
sub sub1()
userform1.show()
end sub
public sub sub2()
msgbox "Now continuing..."
end sub
And then in userform1, set some code on its onClose event:
Private Sub continuebutton()
Call sub2()
end sub

Stop the execution of a macro using another macro(button) using the sendKeys function

I have this Vba code that takes a lot of time to execute and i did this sub to stop the execution, But it didnt work , i used the Sendkeys function.
sub stop ()
SendKeys "{Ctrl,Pause}"
end sub
i want also to resume the execution of my Macro, i tried clicking Ctrl+Break but it didnt resume.
Thank you for helping.
Open VBE and insert a module and copy-paste the below code
Sub Main()
For i = 1 To 100000
DoEvents
Debug.Print i
Next i
End Sub
Sub PauseMacro()
Application.SendKeys "^{BREAK}"
End Sub
Go back to Sheet1 and on the developer tab insert a button and assign the PauseMacro to it.
Now run the Main sub and hit the button to stop the execution of the Main macro
Oh, btw. here's how to use the Application.SendKeys method.
You should avoid using SendKeys.
An approach similar to the one suggested by me how, but without using SendKeys could be this:
Global IsTimeToStop As Boolean
Sub Main()
IsTimeToStop = False
For i = 1 To 100000
DoEvents
Debug.Print i
If IsTimeToStop Then Exit Sub
Next i
End Sub
Sub PauseMacro()
IsTimeToStop = True
End Sub
Replace Global with Dim if this is not a standard module.
What about setting up a watch on a variable that breaks if it changes?
just right click on a variable and add a new watch.

VBA EventHandler firing twice?

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
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 :-)
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

How to stop VBA code running?

Say I have a button embedded into my spreadsheet that launches some VBA function.
Private Sub CommandButton1_Click()
SomeVBASub
End Sub
Private Sub SomeVBASub
DoStuff
DoAnotherStuff
AndFinallyDothis
End Sub
I'd like to have an opportunity to have some sort of a "cancel" button that would stop SomeVBASub execution at an arbitrary moment, and I'm not into involving Ctrl+Break here, 'cause I'd like to do it silently.
I guess this should be quite common issue, any ideas?
Thanks.
Add another button called "CancelButton" that sets a flag, and then check for that flag.
If you have long loops in the "stuff" then check for it there too and exit if it's set. Use DoEvents inside long loops to ensure that the UI works.
Bool Cancel
Private Sub CancelButton_OnClick()
Cancel=True
End Sub
...
Private Sub SomeVBASub
Cancel=False
DoStuff
If Cancel Then Exit Sub
DoAnotherStuff
If Cancel Then Exit Sub
AndFinallyDothis
End Sub
How about Application.EnableCancelKey - Use the Esc button
On Error GoTo handleCancel
Application.EnableCancelKey = xlErrorHandler
MsgBox "This may take a long time: press ESC to cancel"
For x = 1 To 1000000 ' Do something 1,000,000 times (long!)
' do something here
Next x
handleCancel:
If Err = 18 Then
MsgBox "You cancelled"
End If
Snippet from http://msdn.microsoft.com/en-us/library/aa214566(office.11).aspx
Or, if you want to avoid the use of a global variable you could use the rarely used .Tag property of the userform:
Private Sub CommandButton1_Click()
Me.CommandButton1.Enabled = False 'Disabling button so user cannot push it
'multiple times
Me.CommandButton1.caption = "Wait..." 'Jamie's suggestion
Me.Tag = "Cancel"
End Sub
Private Sub SomeVBASub
If LCase(UserForm1.Tag) = "cancel" Then
GoTo StopProcess
Else
'DoStuff
End If
Exit Sub
StopProcess:
'Here you can do some steps to be able to cancel process adequately
'i.e. setting collections to "Nothing" deleting some files...
End Sub
what jamietre said, but
Private Sub SomeVBASub
Cancel=False
DoStuff
If not Cancel Then DoAnotherStuff
If not Cancel Then AndFinallyDothis
End Sub
I do this a lot. A lot. :-)
I have got used to using "DoEvents" more often, but still tend to set things running without really double checking a sure stop method.
Then, today, having done it again, I thought, "Well just wait for the end in 3 hours", and started paddling around in the ribbon. Earlier, I had noticed in the "View" section of the Ribbon a "Macros" pull down, and thought I have a look to see if I could see my interminable Macro running....
I now realise you can also get this up using Alt-F8.
Then I thought, well what if I "Step into" a different Macro, would that rescue me? It did :-)
It also works if you step into your running Macro (but you still lose where you're upto), unless you are a very lazy programmer like me and declare lots of "Global" variables, in which case the Global data is retained :-)
K
~ For those using custom input box
Private Sub CommandButton1_Click()
DoCmd.Close acForm, Me.Name
End
End Sub
This is an old post, but given the title of this question, the END option should be described in more detail. This can be used to stop ALL PROCEDURES (not just the subroutine running). It can also be used within a function to stop other Subroutines (which I find useful for some add-ins I work with).
As Microsoft states:
Terminates execution immediately. Never required by itself but may be placed anywhere in a procedure to end code execution, close files opened with the Open statement, and to clear variables*. I noticed that the END method is not described in much detail. This can be used to stop ALL PROCEDURES (not just the subroutine running).
Here is an illustrative example:
Sub RunSomeMacros()
Call FirstPart
Call SecondPart
'the below code will not be executed if user clicks yes during SecondPart.
Call ThirdPart
MsgBox "All of the macros have been run."
End Sub
Private Sub FirstPart()
MsgBox "This is the first macro"
End Sub
Private Sub SecondPart()
Dim answer As Long
answer = MsgBox("Do you want to stop the macros?", vbYesNo)
If answer = vbYes Then
'Stops All macros!
End
End If
MsgBox "You clicked ""NO"" so the macros are still rolling..."
End Sub
Private Sub ThirdPart()
MsgBox "Final Macro was run."
End Sub

VBA Macro On Timer style to run code every set number of seconds, i.e. 120 seconds

I have a need to run a piece of code every 120 seconds. I am looking for an easy way to do this in VBA. I know that it would be possible to get the timer value from the Auto_Open event to prevent having to use a magic number, but I can't quite get how to fire off a timer to get something to run every 120 seconds.
I don't really want to use an infinite loop with a sleep if I can avoid it.
EDIT:
Cross-post based on an answer provided is at: Excel VBA Application.OnTime. I think its a bad idea to use this... thoughts either way?
When the workbook first opens, execute this code:
alertTime = Now + TimeValue("00:02:00")
Application.OnTime alertTime, "EventMacro"
Then just have a macro in the workbook called "EventMacro" that will repeat it.
Public Sub EventMacro()
'... Execute your actions here'
alertTime = Now + TimeValue("00:02:00")
Application.OnTime alertTime, "EventMacro"
End Sub
Yes, you can use Application.OnTime for this and then put it in a loop. It's sort of like an alarm clock where you keep hittig the snooze button for when you want it to ring again. The following updates Cell A1 every three seconds with the time.
Dim TimerActive As Boolean
Sub StartTimer()
Start_Timer
End Sub
Private Sub Start_Timer()
TimerActive = True
Application.OnTime Now() + TimeValue("00:00:03"), "Timer"
End Sub
Private Sub Stop_Timer()
TimerActive = False
End Sub
Private Sub Timer()
If TimerActive Then
ActiveSheet.Cells(1, 1).Value = Time
Application.OnTime Now() + TimeValue("00:00:03"), "Timer"
End If
End Sub
You can put the StartTimer procedure in your Auto_Open event and change what is done in the Timer proceedure (right now it is just updating the time in A1 with ActiveSheet.Cells(1, 1).Value = Time).
Note: you'll want the code (besides StartTimer) in a module, not a worksheet module. If you have it in a worksheet module, the code requires slight modification.
In Workbook events:
Private Sub Workbook_Open()
RunEveryTwoMinutes
End Sub
In a module:
Sub RunEveryTwoMinutes()
//Add code here for whatever you want to happen
Application.OnTime Now + TimeValue("00:02:00"), "RunEveryTwoMinutes"
End Sub
If you only want the first piece of code to execute after the workbook opens then just add a delay of 2 minutes into the Workbook_Open event
(This is paraphrased from the MS Access help files. I'm sure XL has something similar.) Basically, TimerInterval is a form-level property. Once set, use the sub Form_Timer to carry out your intended action.
Sub Form_Load()
Me.TimerInterval = 1000 '1000 = 1 second
End Sub
Sub Form_Timer()
'Do Stuff
End Sub
I've found that using OnTime can be painful, particularly when:
You're trying to code and the focus on the window gets interrupted
every time the event triggers.
You have multiple workbooks open, you close the one that's supposed to use the timer, and it keeps triggering and reopening the workbook (if you forgot to kill the event properly).
This article by Chip Pearson was very illuminating. I prefer to use the Windows Timer now, instead of OnTime.
My solution:
Option Explicit
Public datHora As Date
Function Cronometro(action As Integer) As Integer
'This return the seconds between two >calls
Cronometro = 0
If action = 1 Then 'Start
datHora = Now
End If
If action = 2 Then 'Time until that moment
Cronometro = DateDiff("s", datHora, Now)
End If
End Function
How to use? Easy...
dummy= Cronometro(1) ' This starts the timer
seconds= Cronometro(2) ' This returns the seconds between the first call and this one