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Databinding: Parser cannot be null

I posted this to the vb.data group, but have had no luck. I'm still very
stuck on this problem...it seems the DataBinding works perfectly the first
time an instance of the form is created. The instance is then destroyed and
a new one is opened and positioning the CurrencyManager in the attached code
fails, with no apparent reason. Any help, even just a general direction
where to look is greatly appreciated. Typing in the specific error
message - i.e. "Parser cannot be null!" into Google and MS hasnt returned
any hits other than this message :-(

I have a TreeView that I am using as a control to navigate a
CurrencyManager . The first time I open the form, everything works as it
should, when I select the nodes in the TreeView the CurrencyManager changes
position and the bound control update accordingly. If I close the form,
then open a new instance of the form the TreeView navigation fails when
setting the CurrencyManager .Position property and returns a message "Parser
cannot be null!". The TreeView's AfterSelect event handler is shown below.
The line causing the message is cm.Position = i

Any thoughts of where to even begin looking for what is causing this
problem?

Thanks
Dave Taylor

Private Sub tvNodes_AfterSe lect(ByVal sender As Object, ByVal e As
System.Windows. Forms.TreeViewE ventArgs) Handles tvNodes.AfterSe lect

If TypeOf tvNodes.Selecte dNode.Tag Is Integer Then

'Lookup node by ID and set the currency manager to the new position

Dim cm As CurrencyManager =
CType(Me.Bindin gContext(App.Co nfig.mbNodeDefs ), CurrencyManager )

Dim dv As DataView = CType(cm.List, DataView)

Dim i As Integer

For i = 0 To (dv.Count - 1)

If CType(dv.Item(i ).Row, dsConfig.mbNode DefsRow).node_i d =
tvNodes.Selecte dNode.Tag Then

cm.Position = i

Exit Sub

End If

Next

End If

End Sub

Nov 21 '05 #1
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