Hashtable and TreeView ?

7 Nov 2006 9:20 PM

Luqman

I am trying to fill the treeview in VB.Net 2005 with Hashtable with the
following code.

my field(0)=emp id
my filed(1)=emp name
my field(2)=manager id
Dim MyNodes As New Hashtable()

Dim node As New TreeNode

Dim dsRow as Datarow

For Each dsRow In ds1.Tables(0).Rows

If IsDBNull(dsRow("MgrID")) Then

Me.TreeView1.Nodes.Add(dsRow("EmpName"))

mynodes.add(dsrow("EmpID"),dsrow("EmpName"))

Else

DirectCast(MyNodes(dsRow("Mgr")), TreeNode).Add(dsRow("Ename")) <-------
this line giving error

End If

Next

Please advise what am I missing ?

Best Regards,

Luqman

8 Nov 2006 11:01 AM

Phill W.

Luqman wrote:

> I am trying to fill the treeview in VB.Net 2005 with Hashtable with the
> following code.
.. . .
> DirectCast(MyNodes(dsRow("Mgr")), TreeNode).Add(dsRow("Ename")) <-------
> this line giving error
.. . .
> Please advise what am I missing ?

The actual error message that's causing you trouble?

I'm /guessing/ it's something like this :

1) MyNodes does not contain the required Manager (it's a little unclear
whether you key these by Mgr or MgrId, but anyway), so

MyNodes( dsRow.Item("Mgr").ToString() )

is returning a Null Reference and calling [null].Add doesn;t work very
well.

Question: Do you /really/ need to load the entire tree in one go?

Personally, I would load just the /Managers/ at the root level and then,
as the user expands each of these, go and retrieve the employee list for
/just/ that manager. It's unlikely that any one user will need to see
/everyone/ all in one go.

HTH,
Phill W.