FIX: ARROW and TAB keys Stop Working in MDI Child Form (145677)

SYMPTOMS

When you have an MDI parent form with a toolbar and one MDI child form, pressing a toolbar button can prevent the arrow keys and tab key from functioning as cursor navigation keys on the MDI child form. You can still type text into the text boxes on the child form, but the cursor can be moved only by using the mouse pointer.

RESOLUTION

To work around this problem, force the toolbar to lose focus. This will prevent the toolbar from trapping the navigation key events. Add the following code to the MouseUp event of the toolbar control:

   Private Sub Toolbar1_MouseUp(Button As Integer, Shift As Integer, _
   x As Single, y As Single)

       Me.SetFocus

   End Sub

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug has been fixed in Visual Basic 5.0 and 6.0.

MORE INFORMATION

Steps to Reproduce

Start a new project in Visual Basic. Form1 is created by default.
Place two text boxes on form1.
Press F4 to bring up Visual Basic's property page and set form1's MDIChild property to true.
Add a MDI parent form to your project, by selecting "MDI Form" from the "Insert" menu.
Add a Toolbar control to your MDI form.

Add the following code to the MDIForm_Load event of the MDI Form:

   Private Sub MDIForm_Load()

       Toolbar1.Buttons.Add
       Form1.Show

   End Sub

Press the F5 key or click Start on the Run menu to start the program.
Click the toolbar button.
Click a text box, to give it keyboard focus. Now try using the cursor or tab keys to reposition the cursor.