BUG: Menu Lost if Caption Changed on Menu with Only WindowList

When a top-level menu has its WindowList property set to True and the top- level menu does not contain any sub-menus, after changing the menu's caption the top-level menu will no longer display the list of MDI child windows and you will not receive any click events.

In order to work around the problem, make sure the top-level menu item that has the WindowList property set to True has at least 1 sub-menu item.

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

In the example below, a menu on the MDI form contains nothing but a WindowList. A command button is placed on the MDI child form with code behind it to change the caption of the menu containing the WindowList. As long as you do not click on the command button, the Window menu will display a list the MDI child windows. Once you click on the command button, the Window menu caption is changed to "Test" and it no longer keeps track of the MDI child windows and it no longer receives click events.

NOTE: Issuing the command "Print MDIForm1.mnuwindow.Windowlist" (without the quotes) from the immediate window will return -1 (True). However, the Window list is not displayed.

Steps To Recreate The Problem

1. Start a new project in Visual Basic (ALT, F, N). Form1 is created by default.
2. From the Property Window, set MDIChild equal to True for Form1.
3. Add a Command button (Command1) to Form1 and add the following code to the Click event.

         Sub Command1_Click ()
            MDIForm1.mnuWindow.Caption = "Test"
         End Sub
   						

4. From the File menu, select New MDI Form. MDIForm1 is created by default.
5. From the Window menu, choose Menu Design.
6. Create a menu for the MDI Form with the following properties:

      Caption   Name        Indented   WindowList
      -------------------------------------------
      File      mnuFile     No         Unchecked
      New       mnuNew      Once       Unchecked
      Window    mnuWindow   No         Checked
   						

7. Choose Done to exit the Menu Design Window. You now have two top-level menus.
8. Add the following code to the Click event of mnuNew menu on MDIForm1.

         Sub mnuNew_Click ()
           Dim f As New Form1
           f.Show
         End Sub
   						

9. Press F5 to run the program.
10. The Window menu will keep track of all the MDIChild windows as long as you do not click Command1 contained in the MDIChild. Once you click on the command button, the Window menu's caption has changed to "Test" and it will no longer list any of the MDIChild windows and you will not receive any click events.