ADT2: Using Scroll Bar Control to Move Through Records

• Microsoft Access Developer's Toolkit version 2.0

SUMMARY

Advanced: Requires expert coding, interoperability, and multiuser skills.

Included in the Microsoft Access Developer's Toolkit (ADT) are three custom OLE controls, similar to those available in Microsoft Visual Basic. Among them is the Scroll Bar control, which you can use to move through records in a form. You must have the ADT installed to use this control.

MORE INFORMATION

This article assumes that you have the ADT installed, and that you are familiar with Access Basic and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Access Basic, please refer to the "Building Applications" manual.

The following example demonstrates how to use the Scroll Bar control:

1. Open the sample database NWIND.MDB.

2. Open the Customers form in Design view. From the Edit menu, choose Insert Object. In the dialog box, select the Insert Control option button. A list of controls will be displayed. If the Scroll Bar control is not listed, choose Add Control, and then select the file MSASB20.OCX from your ADT directory. Select Scroll Bar Control, and then choose OK.

3. Note the scroll bar in the top left corner of the form. Using the right mouse, click the scroll bar, choose Scroll Bar Control Object, and then Properties. Change the orientation from horizontal to vertical, and then choose OK. Size the scroll bar.

4. Using the right mouse button, click the scroll bar, and then choose Properties. Change the Name property to "Scrollbar1" (without the quotation marks).

5. From the View menu, choose Code, and add the following code to the Declarations section of the module:

         Option Explicit
         Dim rec_count As Integer
         Dim rs As Recordset
   

6. In the Object combo box, select Form. In the Procedure combo box, select Load. Add the following code to the Form Load procedure:

         Sub Form_Load ()
            ' Find out how many records are in the form.
             Set rs = Me.recordsetclone
             rec_count = rs.recordcount
   
             ' Initialize the scroll bar properties:
             Me!scrollbar1.object.Max = rec_count
             Me!scrollbar1.object.Min = 0
             Me!scrollbar1.object.SmallChange = 1
             Me!scrollbar1.object.LargeChange = 5
         End Sub
   
   

7. Using the right mouse button, click the scroll bar, and then choose Build Event. Add the following code to the scroll bar's Change event:

         Sub scrollbar1_Change ()
            Dim x As Integer
   
            ' Moves to the first record in the form's dynaset, then moves
            ' .. forward x records, x being the value of the scroll bar.
            rs.MoveFirst
            x = Me!scrollbar1.object.value
            rs.Move x
   
            ' Check to see if at the beginning or end of the
            ' .. recordset, and if so, take appropriate action.
            If rs.eof Then
               rs.MoveLast
            End If
   
            If rs.bof Then
               rs.MoveFirst
            End If
   
            ' Coordinate the form bookmark and the dynaset's bookmark.
            Me.bookmark = rs.bookmark
   
         End Sub
   
   

8. Add the following code to the form's Current event:

         Sub Form_Current ()
            ' Reinitialize the rec_count variable in case records are added.
            rec_count = rs.recordcount
            Me!scrollbar1.object.Max = rec_count
         End Sub
   
   

REFERENCES

Microsoft Access "Building Applications," version 2.0, Chapter 11, "Working With Sets of Records"