Q238406: PRB: Resetting DataCombo RowSource Resets BoundColumn Property

Article: Q238406
Product(s): Microsoft Visual Basic for Windows
Version(s): 6.0,6.0 SP3,6.0 SP5
Operating System(s): 
Keyword(s): kbCtrl kbDataBinding kbVBp600 kbGrpDSVBDB kbGrpDSMDAC kbDSupport kbADO260 kbATM kbmdac2
Last Modified: 23-AUG-2001

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The information in this article applies to:

- Microsoft Visual Basic Professional Edition for Windows, version 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 6.0, 6.0 SP3, 6.0 SP5 
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SYMPTOMS
========

When you programmatically reset the RowSource property of a Visual Basic 6.0
DataCombo or DataList control, the BoundColumn property is reset so that it is
the same as the ListField property. As a result, incorrect data may be inserted
into the Data Source record.

RESOLUTION
==========

To resolve this problem, explicitly set the DataCombo's BoundColumn property to
the correct field name. Then, assign the DataCombo's Text property back to
itself (that is, set the Text property equal to the Text property).

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

When you set the RowSource property of the DataCombo control, it resets the
BoundColumn property to the same field name as the ListField property. You can
see this in the DataCombo's Properties window at design time. When you add a
DataCombo to a form and set the RowSource, RowMember, and ListField properties,
the BoundColumn property initially takes on the same field name as the ListField
property. The same behavior occurs at run time if you reset the RowSource
property in code.

The following sample application demonstrates the problem and the workaround.

Steps to Reproduce:
-------------------

1. In Microsoft Visual Basic 6.0, create a new Standard EXE project.

2. On the Project menu, click Components, and select the following controls:

   - Microsoft ADO Data Control 6.0 (OLEDB)

   - Microsoft DataList Controls 6.0 (OLEDB)

3. Place the following controls onto Form1:

   - ADO Data Control
     Name: ADODC1
     CommandType: adCmdTable
     ConnectionString: Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Nwind.MDB
     RecordSource: Customers

   - DataCombo
     Name: DataCombo1
     RowSource: ADODC1
     ListField: CompanyName
     BoundColumn: CustomerID (note that CompanyName is the default)

   - Command Button
     Name: Command1

   - Command Button
     Name: Command2

4. In Form1's Code window, paste the following code:

  Private Sub Command1_Click()
    MsgBox "Text: " & DataCombo1.Text & ", BoundText: " & DataCombo1.BoundText
  End Sub

  Private Sub Command2_Click()
    With DataCombo1
      Set .RowSource = Adodc1.Recordset
  '    .BoundColumn = "CustomerID"
  '    .Text = .Text
    End With
  End Sub

5. Run the project. In the DataCombo, select a CompanyName.

6. Click Command1. The CompanyName is displayed in the Text property, and the
  5-letter CustomerID is displayed in the BoundText property.

7. Click Command2 to programmatically change the RowSource property. Click
  Command1 again. The BoundText property now displays the CompanyName instead
  of the CustomerID.

8. End the project. Uncomment the two lines in Command2_Click event procedure to
  reset the BoundColumn and Text properties in code.

9. Run the project. Click Command1, click Command2, and then click Command1. The
  BoundText property now displays the CustomerID even after you click Command2.

Additional query words:

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Keywords          : kbCtrl kbDataBinding kbVBp600 kbGrpDSVBDB kbGrpDSMDAC kbDSupport kbADO260 kbATM kbmdac270 kbado270 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600 kbVB600SP3 kbVB600SP5
Version           : :6.0,6.0 SP3,6.0 SP5
Issue type        : kbprb

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