How to use Undo method?

[fredzeppelin]

I have a text box, which I want to allow changes, but with a strong warning to be sure. Proc tied to BeforeUpdate event:

Stolen straight from the Access doc's/examples.

Private Sub Text39_BeforeUpdate(Cancel As Integer)
 
  Dim strMsg As String
  strMsg = "Don't Do It !"
   
  If MsgBox(strMsg, vbExclamation + vbOKCancel, "Are You Sure?") = vbOK Then

     Cancel = False
  Else
     Cancel = True
     Me!Text39.Undo
End If

If I click OK, the textbox stays changed, and the cursor moves on to whatever I did to trigger the control update (eg TAB).

If I click Cancel the Text in the TexBox is selected (highlighted)and the cursor is positioned at chr(0).

I'd hoped that the text would be returned to its pre-edit state and the cursor would do something useful and predicatable based on the update triggering event.

I'm not sure I understand what Cancel and Undo do in this context, and if there's any interaction between them.

I searched the fora and faq's, didn't see anything. If one exists, just point.

(I assume that a Boolean type is just an Integer which is only permitted two values;
0 and -1 ?
Cancel as Integer = True ' hmmmmmmm?
Then the real propellor heads can play all those bit-manipulation games )

Thanks

 

[ProgramError]

Nicked straight from Access created VBA

Private Sub cmdUndo_Click()
On Error GoTo Err_cmdUndo_Click
    DoCmd.DoMenuItem acFormBar, acEditMenu, acUndo, , acMenuVer70
Exit_cmdUndo_Click:
    Exit Sub
Err_cmdUndo_Click:
    MsgBox Err.Description
    Resume Exit_cmdUndo_Click
End Sub

The undo bit is the DoCmd.DoMenuItem ... etc bit



Program Error
Why is it, I still think in terms of spectrum BASIC!

 

[hkaing79]

If you click ok, shouldn't Cancel be True and Else be False?