BUG: UserControl SHIFT+TAB Does Not Follow Tab Sequence

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 6.0

SYMPTOMS

When tabbing through constituent controls contained on a UserControl in reverse order (SHIFT+TAB), only the first constituent control is part of the reverse tab sequence. All controls should be part of the reverse tab sequence unless the TabStop property is set to False. Tabbing forward through the controls works as expected.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

Steps to Reproduce Behavior

1. Start a new Standard EXE project in Visual Basic. Form1 is created by default.



2. From the File menu, add an ActiveX Control project. UserControl1 is created by default.



3. Add three TextBox controls to UserControl1.



4. Close the UserControl1 window and add an instance of UserControl1 to Form1.



5. Add a CommandButton to Form1.



6. Save and run the Project.



7. First, tab through all the controls using the TAB key. Now tab backwards through the controls using the SHIFT+TAB key combination. Observe that the only constituent control that receives focus is the first TextBox.
   
   Bug: Only the first control on the UserControl is included in the reverse tabbing sequence.



8. Return to design mode and add the following code to UserControl1:
   

   
      Option Explicit
      Private Declare Function GetKeyState Lib "user32" _
                      (ByVal nVirtKey As Long) As Integer
   
   
      Private Sub UserControl_EnterFocus()
        Static bEntered As Boolean
        Static FirstCtrl As Control
        Static LastCtrl As Control
        Dim State As Integer
           
        If (GetKeyState(vbKeyTab) And &H1110) = 0 Then
            Exit Sub 'Not entering by pressing Tab, maybe mouse click.
        End If
           
        State = GetKeyState(vbKeyShift) And &H1110 'Eliminate 1st bit.
           
        If bEntered Then 'If already FirstCtrl and LastCtrl are found.
            If State = 0 Then
                FirstCtrl.SetFocus 'Shift key up.
            Else
                LastCtrl.SetFocus 'Shift key down.
            End If
        Else 'If entering first time.
            Dim Ctrl As Control
            Dim nFirst As Integer, nLast As Integer
               
            On Error Resume Next 'There may be controls without tabindex.
            For Each Ctrl In Controls
                If Ctrl.TabIndex <= nFirst Then 'Minimum value.
                    nFirst = Ctrl.TabIndex
                    Set FirstCtrl = Ctrl
                ElseIf Ctrl.TabIndex >= nLast Then 'Maximum value.
                    nLast = Ctrl.TabIndex
                    Set LastCtrl = Ctrl
                End If
            Next
            bEntered = True 'Entered once.
        End If
          
      End Sub
   
    




9. Save and run the project again. This time the SHIFT+TAB sequence loops through all the controls in the UserControl.

Additional query words: kbDSupport kbDSD kbVBp kbVBp600bug kbCtrlCreate

Keywords : kbGrpVB
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbbug