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Q281940: BUG: DBCombo SelectedItem Property Is Not Updated When You Type

Article: Q281940
Product(s): Microsoft Visual Basic for Windows
Version(s): 6.0
Operating System(s): 
Keyword(s): kbCtrl kbVBp kbVBp600bug kbGrpDSVB kbDSupport kbCodeSnippet
Last Modified: 08-MAY-2002

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The information in this article applies to:

- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
- Microsoft Visual Basic Professional Edition for Windows, version 6.0 
- Microsoft Visual Basic Learning Edition for Windows, version 6.0 
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SYMPTOMS
========

When you use the type-ahead searching features of the DBCombo control from
DBList32.ocx, the SelectedItem property is not updated, and DBCombo does not
reflect the matching entry that is found.

RESOLUTION
==========

A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem. This fix may receive additional
testing at a later time, to further ensure product quality. Therefore, if you
are not severely affected by this problem, Microsoft recommends that you wait
for the next Visual Studio service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services
to obtain the fix. For a complete list of Microsoft Product Support Services
phone numbers and information about support costs, please go to the following
address on the World Wide Web:

  http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal support costs will apply to additional
support questions and issues that do not qualify for the specific update in
question.

NOTE: You must have a Visual Studio license agreement to obtain this fix.



STATUS
======

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

MORE INFORMATION
================

When you select an item in the list portion of a DBCombo control, the
SelectedItem property contains a bookmark that you can use to reposition the
selected record in the Recordset of the Data control that the RowSource property
specifies. This property should be updated whether the user uses a mouse or the
keyboard to select the item. Thus, when you use the type-ahead searching feature
of this control, you expect that the SelectedItem property is updated after you
type a name that matches a name in the list and press the ENTER key. In
addition, the text in DBCombo should reflect the matching entry that is found.
However, this functionality does not work when you use the standard Databound
Combo and the Intrinsic Data control that shipped with Visual Basic 6.0.

Steps to Reproduce Behavior
---------------------------

1. Create new Standard EXE project. Form1 is created by default.

2. From the Project menu, click Components, select the "Data Bound List Controls
  6.0" check box, and then click OK.

3. Add a Databound combo, DBCombo1, to Form1.

4. Add two TextBox controls, Text1 and Text2.

5. Add a Data control, Data1.

6. Configure the property settings of these controls as follows:

  Data1 - Data control
  DatabaseName = Biblio.mdb
  RowSource = Authors
  ReadOnly = True

  Text2 - TextBox control
  DataSource = Data1
  DataField = Author
  Visible = False

  DBCombo1 - Databound Combo control
  RowSource = Data1
  ListField = Author

7. Add the following code to the General Declarations section of Form1:

  Option Explicit

  Private Const UP_ARROW = 38
  Private Const DOWN_ARROW = 40
      
  Private Sub Data1_Reposition()
     '
     ' Copy Text from Bound Text2 to Unbound Text1.
     Text1.Text = Text2.Text
  End Sub
      
  Private Sub DBCombo1_KeyUp(KeyCode As Integer, Shift As Integer)
     Dim bmk As Variant
     Dim x As Integer
     Dim msg As String

     On Error GoTo ErrHandler
     '
     ' Save Bookmark on CR and Arrow Key Activity.
     Select Case KeyCode
        Case Asc(vbCr), UP_ARROW, DOWN_ARROW
            msg = "DBCombo1.SelectedItem has the value "
            bmk = DBCombo1.SelectedItem
            ' The next line raises error 13 if bmk has no value.
            For x = 0 To UBound(bmk)
                msg = msg & bmk(x)
            Next x
            Data1.Recordset.Bookmark = bmk
            Debug.Print msg
     End Select
     Exit Sub
              
  ErrHandler:
     If Err.Number = 13 Then   ' Type mismatch
        Debug.Print "DBCombo1.SelectedItem is not assigned a value."
     Else
        MsgBox "Error " & Err.Number & ": " & Err.Description, vbCritical _
           + vbOKOnly
     End If
  End Sub

  Private Sub Form_Load()
     Text1.Text = ""
     DBCombo1.Text = ""
  End Sub

8. Run the project, and type a name that matches an entry in the bound DBCombo
  control (such as "Curry, Dave" (without the quotation marks)).

9. Press ENTER. Notice that the DBCombo1.SelectedItem property is not updated.

10. Clear the text in DBCombo, and type a name that matches an entry in the list
  (such as "Wellin, Paul" (without the quotation marks)).

11. Press the UP ARROW or DOWN ARROW key. Notice that DBCombo1.SelectedItem is
  updated with the bookmark for "Wellin, Paul".

Additional query words:

======================================================================
Keywords          : kbCtrl kbVBp kbVBp600bug kbGrpDSVB kbDSupport kbCodeSnippet 
Component         : Component
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600
Version           : :6.0
Issue type        : kbbug kbprb
Solution Type     : kbpending

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