ACC97: How to Dim Menu Items or Disable Toolbar Buttons in Visual Basic for Applications

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The CommandBars collection in Microsoft Access 97 exposes all menu bars, toolbars, and shortcut menus in your application to Visual Basic for Applications so you can manipulate them programmatically. Using the properties and methods of the CommandBars collection in your application, you can manipulate and customize both built-in and custom command bars.

NOTE: If you use Windows application programming interface (API) procedures to manipulate menus in your Microsoft Access 2.0 or 7.0 database, you must modify the code to use the CommandBars object model in Visual Basic for Applications when you convert your database to Microsoft Access 97. Windows API calls do not work with Microsoft Access 97 menus, toolbars, or shortcut menus.

Each command bar, whether it is a menu bar, a toolbar, or a shortcut menu, consists of a collection of CommandBarControl objects. You can create three types of CommandBarControls on a command bar, each with its own methods and properties:

• CommandBarButton represents a button control on a command bar, which can display text, an icon, or both together.
• CommandBarComboBox represents a custom edit box, drop-down list box, or combo box on a command bar.
• CommandBarPopup represents a control on a command bar that displays another menu when you click it; the menu that appears is another command bar associated with the popup control.

You refer to a control on a command bar by its Caption property or Index number. For example, if a control on the "Test" command bar has the caption "ClickMe" and an index value of 1, then the following two statements both refer to the same control: The following example shows you how to disable or enable items on a menu bar or toolbar based on events in your application.

1. Open the sample database Northwind.mdb.
2. Create a new form not based on any table or query in Design view, and save it as frmChangeBars.
3. Enable the Control Wizards button on the Toolbox toolbar, and then add an option group control to the detail section of the form.
   1. In the "What label do you want for each option?" dialog box, type the following four labels, each in its own row: Dim View Menu, Dim Print Button, Dim New Database and Enable All. Click Next.
   2. In the "Do you want one option to be the default choice?" dialog box, click "No, I don't want a default," and then click Next.
   3. In the "What value do you want to assign to each option?" dialog box, click Finish.
4. Set the Name property of the option group control to CommandBarTest, and set the AfterUpdate property to the following event procedure:

         Private Sub CommandBarTest_AfterUpdate()
            Dim CBarMenu as CommandBar, CBarTool as CommandBar
            Dim CBarCtl as CommandBarPopup
            ' Set the CommandBar objects to the menu bar and toolbar that
            ' display when you open a form in Form view.
            Set CBarMenu = CommandBars("NorthwindCustomMenuBar")
            Set CBarTool = CommandBars("Form View")
            ' Because the File menu is a Popup control, assign it to an object
            ' variable so you can manipulate its CommandBar object.
            Set CBarCtl = CBarMenu.Controls("File")
   
            ' Program what happens when you click an option.
            Select Case Me!CommandBarTest
               ' You clicked Dim View Menu.
               Case 1
                  CBarMenu.Controls("View").Enabled = False
   
               ' You clicked Dim Print Button.
               Case 2
                  CBarTool.Controls("Print...").Enabled = False
   
               ' You clicked Dim New Database.
               Case 3
                  CBarCtl.CommandBar.Controls("New Database...").Enabled = _
                     False
   
               ' You clicked Enable All.
               Case 4
                  CBarMenu.Controls("View").Enabled = True
                  CBarTool.Controls("Print...").Enabled = True
                  CBarCtl.CommandBar.Controls("New Database...").Enabled = _
                     True
            End Select
         End Sub
   					

5. Open the frmChangeBars form in Form view.
6. Click Dim View Menu and note that the View menu at the top of your screen dims.
7. Click Dim Print Button and note that the Print button on the Form View toolbar dims.
8. Click Dim New Database and note that the New Database selection on the File menu dims.
9. Click Enable All to re-enable all three controls.