Can't create DataAdapter in code that's available throughout form
In form_load I write the following code:
Dim daC As New OleDbDataAdapter("SELECT * FROM Concepts",
cnConcepts)
dsC.Concepts.Constraints.RemoveAt(1)
daC.Fill(dsC, "Concepts")
dsC.Concepts.ActiveColumn.DefaultValue = True
This Kevin Yu will be familiar with. It fills a series of listboxes with
concepts. In some of the listboxes a New button will appear above the
listbox. Clicking the New button will bring up a form in addnew mode only
for concepts with the proper ParentID. It all works fine.
The problem arises when I want to clear and refill the listboxes, so that
the new entry in the appropriate listbox will show. Here is part of the code
for the appropriate New button.
Dim frm As New frmNewConcept
With frm
'.iNew = Me.lstConcepts0.SelectedValue this is true for all the
others
.iNew = 0
.iNewAddMode = True
.ShowDialog()
End With
If frm.iAddNumber > 0 Then
dsC.Clear()
daC.Fill(dsC, "Concepts")
End If
Of course it won't compile. In the New button I get the message 'Name daC is
not declared'.
I tried declaring daC on the form level
Dim daC As New OleDbDataAdapter("SELECT * FROM Concepts", cnConcepts).
It will compile, but I get the runtime error,
SystemInvalidOperationException. The select command property has not been
initialized before calling 'Fill'.
...
at system.data.common at dbdataadapter.fill(DataSet.dataset, strSourceTable)
...
at TopicFromStart_Load...line 1386
Line 1386
Line 1386 is daC.Fill(dsC, "Concepts")
My question is how do I code a DataApapter in a form so that it fills the
Dataset and also is available to other controls' event procedures.
Thank you in advance.
Dennis