Disable navigation button

[didajosh]

I have made a form and added navigation buttons using the wizard.
When the focus is on the first Record, I want the "Previous Record Button" to disable.
So in the code in Click event I want to write something like:

If Current Record = BOF
then Command82.Enabled = False 
End if

How do I write this...?

[patjones]

Hi -

If this is a bound form, you could try putting this in the On Current event for the form:

Dim rst As Recordset
Set rst = Me.RecordsetClone

If rst.BOF Then
     cmdPreviousRecord.Enabled = False
Else
     cmdPreviousRecord.Enable = True
End If

A shorthand way of writing the If construct is:

cmdPreviousRecord.Enabled = Not rst.BOF

Pat

[NeoPa]

I have had problems with this logic before, which I must admit I never really got to the heart of. I forget under which circumstances I found .BOF & .EOF to be unreliable, but they were what I tried first.

With Me
    'Bug where .AbsolutePosition can be 0 even when on NewRecord
    .cmdPreviousRecord.Enabled = ((.Recordset.AbsolutePosition > 0) Or _
                                 (.NewRecord))
...
End With

[patjones]

I have successfully used .BOF and .EOF in various contexts before; however in looking at what I wrote yesterday I don't think putting the code

Dim rst As Recordset
Set rst = Me.RecordsetClone

in with the rst.BOF test will work because the assignment of rst will, I think, automatically place the bookmark on the first record; so rst.BOF would just always evaluate to true.

I'm going to make a little mock-up form and play with this, pending completion of some matters here at work.

Pat

[didajosh]

Hi,
Thank you for your time and suggestions.
I tried to implement what zepphead80 told me.

I don't think rst.BOF would just always evaluate to true, on the contrary its always evaluating as False. I put a couple of msg boxed to check if the condition is being satisfied or not (following code) but turns out "True" msgbox never appears.

   Dim rst As Recordset
   Set rst = Me.RecordsetClone
   If rst.BOF Then
   MsgBox "True"
   CmdPrevButton.Enabled = False
   Else
   MsgBox "False"
   CmdPrevButton.Enabled = True
   End If

The button remains enabled.

Dipali

[patjones]

Dipali -

The button will in fact turn gray.

As I mentioned in my post this morning, I didn't think this code would work properly. I have a mock database set up to test out how to do this and I'll let you know what I come up with, shortly.

Pat

[didajosh]

Hi,
I guess I found a solution.

 Dim rst As Recordset
   Set rst = Me.Recordset
   If rst.AbsolutePosition = 0 Then
   Command28.Enabled = False
   Else
   Command28.Enabled = True
   End If

It works perfectly. I just stumbled on "AbsolutePositi on".
I am not sure if its alright to use it, or if this is the right way.

-Dipali

[patjones]

Hi Dipali -

That is in fact what I basically did as well. Upon researching BOF I remembered an important fact, which is that it doesn't get set to false until you are actually on the first record AND try to move to a previous record (same thing for EOF, at the last record).

What I ended up doing was declaring a recordset visible to the entire form module, "rst". I then coded the Form Open event, and Click events for the two command buttons as follows:

Private Sub cmdNext_Click()

Me.cmdPrevious.Enabled = True

If rst.AbsolutePosition < rst.RecordCount - 1 Then

    rst.MoveNext
    Me.Bookmark = rst.Bookmark

    If rst.AbsolutePosition = rst.RecordCount - 1 Then
        Me.cmdPrevious.SetFocus
        Me.cmdNext.Enabled = False
    End If
    
End If

End Sub

Private Sub cmdPrevious_Click()

Me.cmdNext.Enabled = True

If rst.AbsolutePosition > 0 Then
    
    rst.MovePrevious
    Me.Bookmark = rst.Bookmark
    
    If rst.AbsolutePosition = 0 Then
        Me.cmdNext.SetFocus
        Me.cmdPrevious.Enabled = False
    End If
        
End If

End Sub

Private Sub Form_Open(Cancel As Integer)

Set rst = Me.RecordsetClone
rst.MoveLast
rst.MoveFirst
Me.Bookmark = rst.Bookmark
Me.cmdPrevious.Enabled = False

End Sub

Let me know what you think.

Pat

[didajosh]

Hi Pat,
Thank you for your generous help. I really appreciate it.
I need to try this and will get back with you.

Dipali

[NeoPa]

Hi Dipali.

From your comments I assume you didn't notice my post #3 from earlier. .AbsolutePositi on is good, but as you'll see from that post, it's not perfect on its own. You would also need to test .NewRecord if you want the code to work logically.

[didajosh]

Hi,
Thank you so much for the help.I am very grateful to you guys.
I clubbed the two solutions suggested to me.
It works perfectly.
Its in the Current event of the form. And its for previous, next, first and last buttons.

With Me
  CmdPreviousRecord.Enabled = ((.Recordset.AbsolutePosition > 0) Or (.NewRecord))
  CmdNextRecord.Enabled = ((.Recordset.AbsolutePosition <> .Recordset.RecordCount - 1) Or (.NewRecord))
  CmdFirstRecord.Enabled = ((.Recordset.AbsolutePosition > 0) Or (.NewRecord))
  CmdLastRecord.Enabled = ((.Recordset.AbsolutePosition <> .Recordset.RecordCount - 1) Or (.NewRecord))
End With

[NeoPa]

That's very good thinking. You have clearly grasped the point and built on it.

I would consider slight changes though, to support the logic :

With Me.
  .CmdPreviousRecord.Enabled = ((.Recordset.AbsolutePosition > 0) Or (.NewRecord))
  .CmdNextRecord.Enabled = (Not .NewRecord)
  .CmdFirstRecord.Enabled = ((.Recordset.AbsolutePosition > 0) Or (.NewRecord))
  .CmdLastRecord.Enabled = ((.Recordset.RecordCount > 0) And (.Recordset.AbsolutePosition <> .Recordset.RecordCount - 1))
End With