DOCUMENT:Q189998  07-AUG-1998  [vbwin]
TITLE   :BUG: Data Environment: MSHFlexGrid Rebinding Data
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:6.0
OPER/SYS:WINDOWS
KEYWORDS:

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The information in this article applies to:

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

Attempting to rebind the MSHFlexGrid to a different Data Environment as the
DataSource property results in an error:

   Runtime Error 30022, The Hierarchical FlexGrid does not support the
   requested type of data binding.

CAUSE
=====

If the MSHFlexGrid.DataMember is set to a Data Environment other than the
original, the MSHFlexGrid attempts to rebind the data using the previous
DataSource property setting. Because the same Command does not exist in the
subsequent Data Environment, an error results.

RESOLUTION
==========

To work around this problem, set MSHFlexGrid.DataSource = Nothing before
rebinding to the next Data Environment.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed
at the beginning of this article. We are researching this bug and will post
new information here in the Microsoft Knowledge Base as it becomes
available.

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

1. Create a new Visual Basic Standard.Exe project.Form1 is created by
   default.

2. From the <Project-Components-Controls> menu, check the selection for
   <Microsoft Hierarchical FlexGrid Control 6.0 (OLEDB)>.

3. Add a MSHFlexGrid to the form.

4. From the <Project-Add Data Environment> menu, create a new Data
   Environment.

5. Right-click the Connection icon and, under the Provider tab, select
   <Microsoft Jet OLEDB Provider>. On the Connection tab, click the
   ellipse button, choose the NWind.MDB, and then click OK.

6. Right-click the Connection icon again, and select <Add Command>.

7. Right-click on Command, and select <Properties>. Select <Table> as
   the database object source, and select <Employees> for the Object Name.

8. Right-click the Command icon and select <Rename>. Rename the
   Command to <test1>.

9. Repeat steps 4-7 to create a second Data Environment. Do not rename
   the second Command.

10. Add two CommandButtons to the form and paste the following code into
   each respectively.

      Private Sub Command1_Click()
         'Set MSHFlexGrid1.DataSource = Nothing
         MSHFlexGrid1.DataMember = "test1"
         Set MSHFlexGrid1.DataSource = DataEnvironment1
      End Sub

      Private Sub Command2_Click()
         'Set MSHFlexGrid1.DataSource = Nothing
         MSHFlexGrid1.DataMember = "command1"
         Set MSHFlexGrid1.DataSource = DataEnvironment2
      End Sub

11. Run the project and click on ommand1. The MSHFlexGrid should be
   populate with the results. Click on Command2. You should receive an
   error indicating:

      The Hierarchical FlexGrid does not support the requested type of data
      binding.

12. Uncomment the commented out lines in the CommandButtons. Repeat step
   11. You should not receive an error attempting to rebind the Data
   Environment.

REFERENCES
==========

Visual Basic Books Online, "The Data Environment"

Additional query words: kbVBp600bug kbDSupport kbdse kbDatabase kbVBp
kbDataBinding kbCtrl
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Version           : WINDOWS:6.0
Platform          : WINDOWS
Issue type        : kbbug

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