DOCUMENT:Q251225 23-AUG-2001 [vbwin] TITLE :BUG: Recordset EditMode Not Properly Set with DataCombo PRODUCT :Microsoft Visual Basic for Windows PROD/VER:WINDOWS:6.0 OPER/SYS: KEYWORDS:kbComboBox kbCtrl kbDatabase kbDataBinding kbListBox kbVBp600bug kbGrpDSVBDB kbGrpDSMDA ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Professional Edition for Windows, version 6.0 - Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 ------------------------------------------------------------------------------- SYMPTOMS ======== When using some controls bound to an ADO Recordset object, the EditMode is not set properly when you modify the data through the bound controls. These controls include the Microsoft DataCombo control. With other controls bound to an ADO Recordset object, the EditMode is set properly when data is changed through the bound controls. These controls include the TextBox. The expected behavior is that the EditMode is set properly for each type of bound control. CAUSE ===== The affected controls do not notify the Binding Collection that they are dirty. RESOLUTION ========== There are several possible workarounds for this problem: - Bind the control to an ADO DataControl or to a DataEnvironment instead of an ADO Recordset object so the that the EditMode is set properly. - Check in the LostFocus event of the control to see if the control's value has changed. If it has, copy the change to the underlying recordset. - Execute the recordset's Move method with a value of 0 to immediately post the control's change. You could execute this method in the control's Change event, for example. - Bind the control to a BindingCollection object. When using a BindingCollection object, the EditMode property is set properly. 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 ------------------ This sample uses the Biblio database that comes with Visual Basic. 1. In Microsoft Visual Basic, create a new Standard EXE project. Form1 is created by default. 2. From the Project menu, select References, and then select the Microsoft ActiveX Data Objects Library. Click OK. 3. From the Project menu, choose Components, and select the Microsoft DataList Controls 6.0 (OLEDB). Click OK. 4. Place a DataCombo, a TextBox, and a CommandButton on Form1. 5. Paste the following code into Form1's code window: Private cn As ADODB.Connection Private rs As ADODB.Recordset Private Sub Command1_Click() 'Display the current EditMode of the ADO Recordset. MsgBox "Current EditMode is (0 = adEditNone):" & rs.EditMode End Sub Private Sub DataCombo1_LostFocus() 'Uncomment the following code, to work around using the LostFocus 'event: 'If DataCombo1.Text <> rs(DataCombo1.DataField).Value Then ' rs(DataCombo1.DataField).Value = DataCombo1.Text 'End If End Sub Private Sub DataCombo1_Change() 'Uncomment the following line, to work around using the Move method. 'rs.Move 0 End Sub Private Sub Form_Load() Set cn = New ADODB.Connection cn.Open "Provider=Microsoft.Jet.OLEDB.3.51;Data Source=BIBLIO.MDB" Set rs = New ADODB.Recordset rs.CursorLocation = adUseClient rs.Open "Titles", cn, adOpenStatic, adLockOptimistic 'Display the list of Titles in the DataCombo Set DataCombo1.RowSource = rs DataCombo1.ListField = "Title" 'Bind the DataCombo to the ADO Recordset Set DataCombo1.DataSource = rs DataCombo1.DataField = "Title" 'Bind the Text Box to the ADO Recordset Set Text1.DataSource = rs Text1.DataField = "Title" End Sub 6. If necessary, modify the connection string in the statement that opens the connection. You might need to modify the Provider to use the version of the Microsoft Jet OLE DB Provider that is on your system. You also might need to modify the Data Source to use the copy of the Biblio database that is on your system. 7. Start the project. 8. From the list of Titles displayed in the DataCombo, select a different Title. Click Command1, and note that the EditMode is still 0, which is adEditNone. 9. Modify the Title in the TextBox and click Command1. Note that the the EditMode is set correctly to 1, which is adEditInProgress. Workaround Using the LostFocus event ------------------------------------ 1. Uncomment the following code in the event DataCombo1_LostFocus(): If DataCombo1.Text <> rs(DataCombo1.DataField).Value Then rs(DataCombo1.DataField).Value = DataCombo1.Text End If 2. Restart the project. 3. From the list of Titles displayed in the DataCombo, select a different Title. Click Command1, and note that the EditMode is set correctly. Workaround Using the Move Method -------------------------------- 1. Re-comment the line of code in the event DataCombo1_LostFocus(), by placing apostrophes (') in front of the code. 2. Uncomment the following line of code in the event DataCombo1_Change(): rs.Move 0 3. Restart the project. 4. From the list of Titles displayed in the DataCombo, select a different Title. Click Command1, and note that the change is posted to the recordset immediately. For example, selecting in the DataCombo immediately updates the bound TextBox. Workaround Using the BindingCollection Object --------------------------------------------- 1. From the Project menu, choose References, and select the Microsoft Data Binding Collection. Click OK. 2. Replace all of the existing code from Form1's code window with the following: Option Explicit Private cn As ADODB.Connection Private rs As ADODB.Recordset Private myBindingCollection As BindingCollection Private Sub Command1_Click() MsgBox "Current EditMode is (0 = adEditNone):" & rs.EditMode End Sub Private Sub Form_Load() Set cn = New ADODB.Connection cn.Open "Provider=Microsoft.Jet.OLEDB.3.51;Data Source=BIBLIO.MDB" Set rs = New ADODB.Recordset rs.CursorLocation = adUseClient rs.Open "Titles", cn, adOpenStatic, adLockOptimistic 'Display the list of Titles in the DataCombo Set DataCombo1.RowSource = rs DataCombo1.ListField = "Title" 'Bind the DataCombo to the ADO Recordset Set myBindingCollection = New BindingCollection Set myBindingCollection.DataSource = rs With myBindingCollection .Clear .Add DataCombo1, "BoundText", "Title" End With 'Bind the Textbox to the ADO Recordset Set Text1.DataSource = rs Text1.DataField = "Title" End Sub 3. If necessary, modify the connection string in the statement that opens the connection. 4. Restart the project. 5. From the list of Titles displayed in the DataCombo, select a different Title. Click Command1, and note that the EditMode is set correctly. REFERENCES ========== For additional information, please see the following topics in the Microsoft Visual Basic 6.0 Online Help index: - DataCombo control - BindingCollection object Additional query words: ====================================================================== Keywords : kbComboBox kbCtrl kbDatabase kbDataBinding kbListBox kbVBp600bug kbGrpDSVBDB kbGrpDSMDAC kbDSupport Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600 Version : WINDOWS:6.0 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. 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