Proper way of canceling process?

[softwareguy74]

Hi,

What is the proper way to let the user cancel a running process?

For example, I have an application which when the user clicks the start button, a function is called and begins it's processing.. I have included a Cancel button on the form just in case the user does not want to complete the processing.

What I did is created a msgbox that pops up when the user hits Cancel which asks them if they really wish to cancel the process. If they hit Yes, then it stop, otherwise, it continues.

Here's the code I used:

Private Sub cmdCancel_Click()
    Dim xVar As Integer
    
    xVar = MsgBox("Are you sure you wish to cancel?", _
          vbQuestion + vbYesNo)
    
    If xVar = 6 Then
        '-- cancel operation
        Unload Me
    End If
    
End Sub

But I think I'm missing something because the following situation occurs:

When the user clicks Cancel and hits Yes, the Form unloads but an error occurs because the process that is being canceled was using an ADO recordset and I put RS.Close in the Form_Unload event to close the connection but it seems that the process wants to keep continuing. The error states "Operation is not allowed when the object is closed."

This is obviously due to the fact that I'm closing the recordset but I have no choice. I do not want to keep it open.

My question is, how do I stop the process dead in it's tracks if the user selects Yes so that it does not try to process any further?

Any help would be appreciated..

Dan

Try this:

Private Sub cmdCancel_Click()
    Dim xVar As Integer
    
    xVar = MsgBox("Are you sure you wish to cancel?", _
          vbQuestion + vbYesNo)
    
    If xVar = 6 Then
        '-- cancel operation
        Unload Me
        Set Form1 = Nothing
        End
    End If
    
End Sub

[DrewDog_21]

In the function or subroutine where the ADO recordset is
processing, use an error handling routine, like this:

On Error GoTo Database_Error

'put your loop or process or whatever here
myRecordset.PerformWhateverFunctionYouAreDoing

Exit Sub 'exit the subroutine

Database_Error:
     Select Case Err.Number
          Case 1234567890 'replace this with the number of
'the error that occurs.  I have seen that error before but
'I can't remember the number
               Exit Sub 'leave the subroutine without 
'showing an error message
           Case Else 'other error occured
                msgbox "Error & " Err.Number & ": " & Err.Description, vbCritical
     End Select

End Sub

[Edited by DrewDog_21 on 09-16-2000 at 01:33 PM]

If you want to ignore the message just put
"On error resume next" under whatever subroutine the error occurs


Like this:

Private Sub cmdCancel_Click()
On error resume next
Dim xVar As Integer

xVar = MsgBox("Are you sure you wish to cancel?", _
vbQuestion + vbYesNo)

If xVar = 6 Then
'-- cancel operation
Unload Me
End If

End Sub









Or you can go a step further and do this

Private Sub cmdCancel_Click()
On error goto getdahellouttahere
Dim xVar As Integer

xVar = MsgBox("Are you sure you wish to cancel?", _
vbQuestion + vbYesNo)

If xVar = 6 Then
'-- cancel operation
Unload Me
End If
getdahellouttahere:
exit sub
End Sub




but the most simple way would to just:

Private Sub cmdCancel_Click()
Dim xVar As Integer

xVar = MsgBox("Are you sure you wish to cancel?", _
vbQuestion + vbYesNo)

If xVar = 6 Then
'-- cancel operation
Unload Me <-----Replace this simply with "Exit Sub"
End If

End Sub






Have Phun



"There is more than one way to skin a cat"