BUG: Unable to Tab Through Controls on UserControl

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0

SYMPTOMS

When a UserControl containing constituent controls is placed on a form, while the UserControl is the only control on the form, tabbing through the constituent controls does not loop.

CAUSE

This is because Visual Basic treats the UserControl as one control. Because there is no other control to give focus to, no looping occurs.

RESOLUTION

Manually set focus to the control with the TabIndex of 0 in the KeyPress event of the last control in the tab sequence. See the MORE INFORMATION section below for sample code.

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 CommandButton controls to UserControl1.



4. Close the UserControl1 window and add an instance of UserControl1 to Form1.
   
   Note: In order to reproduce this problem, UserControl1 should be the only control on Form1.



5. Save and run the project. Begin pressing the TAB key to tab through all the controls. Notice that the tab sequence does not loop through the controls on the UserControl.



6. Stop the project and add the following code to the KeyPress event of the last control in the tab sequence for the UserControl:

   
         Private Sub Command3_KeyPress(KeyAscii As Integer)
            Dim Ctrl As Control
            Dim FirstTab As Integer
            Dim FirstCtrl As Control
            Dim Count As Integer
   
            Count = 0
            ' Loop though all the controls and find
            ' the last control in the tab order
            For Each Ctrl In Controls
               If Count = 0 Then
                  FirstTab = Ctrl.TabIndex
                  Set FirstCtrl = Ctrl
               End If
               If Ctrl.TabIndex < FirstTab Then
                  FirstTab = Ctrl.TabIndex
                  Set FirstCtrl = Ctrl
               End If
               Count = Count + 1
            Next Ctrl
   
            ' Set focus to last control in the tab order
            If KeyAscii = 9 Then
               FirstCtrl.SetFocus
            End If
         End Sub
    




7. Save and run the project again. Note that the tab sequence now loops through all the controls on the UserControl.

Additional query words: kbDSupport kbDSD kbVBp kbVBp600bug kbVBp500bug kbCtrlCreate

Keywords : kbGrpVB
Version : WINDOWS:5.0,6.0
Platform : WINDOWS
Issue type : kbbug