ACC97: Overlapping List Box Controls Show Through One Another

• Microsoft Access 97

SYMPTOMS

Moderate: Requires basic macro, coding, and interoperability skills.

When your form contains two or more list box controls, one on top of the other, you can see portions of the control on the bottom when you click the one on top.

This article assumes that you are familiar with Visual Basic for Applications and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Visual Basic for Applications, please refer to the "Building Applications with Microsoft Access 97" manual.

RESOLUTION

You can work around this behavior by setting the Visible property of the underlying list box control(s) to False when not in use. The following example uses a command button to toggle the Visible properties of two list box controls.

1. Start Microsoft Access and open the sample database Northwind.mdb.

2. Create a new form not based on any table or query in Design view. Be sure to add the list box controls in the order listed below so List2 is on top of List0:

         Form: frmListBox
         ------------------------
         Caption: Test List Boxes
   

         List Box:
            Name: List0
            RowSource: Employees
            ColumnCount: 2
            ColumnWidths: .25";1"
            Visible: Yes
            Left: 1"
            Top: .25"
            Width: 1.75"
            Height: 1.3"
         List Box:
            Name: List2
            RowSource: Customers
            ColumnCount: 2
            ColumnWidths: 0";1.25"
            Visible: No
            Left: 1"
            Top: .25"
            Width: 1.75"
            Height: 1.3"
         Command Button:
            Name: Command0
            Caption: Toggle Boxes
            OnClick: [Event Procedure]
   
   

3. Set the command button's OnClick property to the following event procedure:

         Private Sub Command0_Click
            'Toggle the Visible property of each list box
            List0.Visible = Not List0.Visible
            List2.Visible = Not List2.Visible
         End Sub
   
   

4. Switch the form to Form view. A list of ID numbers and last names from the Employees table is displayed in the List0 list box.

5. Click the Toggle Boxes button. A list of company names from the Customers table is displayed in the List2 list box.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Access 97. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Problem

If you overlap two list boxes and toggle the Visible property of just one of them, you can see portions of the underlying list box control. This behavior does not occur in earlier versions of Microsoft Access.

1. Perform steps 1 and 2 in the "Resolution" section of this article.

2. Set the command button's OnClick property to the following event procedure:

         Private Sub Command0_Click
            'Toggle the Visible property of the top list box
            List2.Visible = Not List2.Visible
         End Sub
   
   

3. Switch the form to Form view. You can select information from the Employees table in the List0 list box with no problems.

4. Click the Toggle Boxes button. Note that as you scroll up and down the List2 list box and click company names, you see portions of the List0 list box underneath. This is because the Visible property of the List0 list box is still set to True.