Treeview Nodes.Clear

3 Feb 2006 6:30 PM

Dianna

Hi,

I am trying to clear my treeview when I add new items (to refresh) and It
only seems to be removing the first Parent Node, none of the children below
are being cleared.

Am I doing something wrong? The below code is based on retreiving data from
a hierarchical table:
Thanks,Dianna

    Private Sub PopulateTreeView()

        treeEvents.Nodes.Clear()

        Dim cmd As String

        cmd = "Select * From dbo.fncGetEventTree(null) ORDER BY lineage +
Ltrim(Str(node,6,0))"

        Dim da As New System.Data.SqlClient.SqlDataAdapter(cmd,
ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)

        da.Fill(ds)

        treeEvents.Nodes.Add(New TreeNode("Event Groups"))

        Dim tNode As New TreeNode

        tNode = treeEvents.Nodes(0)

        PopulateTreeView(0, tNode)

        tNode.Expand()
    End Sub

    Private Sub PopulateTreeView(ByVal inParentID As Integer, ByRef
inTreeNode As TreeNode)

        Dim newtag As String

        dv = New DataView(ds.Tables(0))

        dv.RowFilter = "parent_id = " & inParentID

        Dim drv As DataRowView

        For Each drv In dv

            Dim parentnode As TreeNode

            parentnode = New TreeNode(drv.Item("event"))

            inTreeNode.Nodes.Add(parentnode)

            parentnode.Tag = newtag

            'call the routine again to find childern of this record.
            PopulateTreeView(drv.Item("event_id"), parentnode)

        Next drv

    End Sub

4 Feb 2006 3:28 PM

pvdg42

Show quote

"Dianna" <Dia***@discussions.microsoft.com> wrote in message
news:D4C973D4-721A-4DC8-8A40-AE34E9A5CF1A@microsoft.com...
> Hi,
>
> I am trying to clear my treeview when I add new items (to refresh) and It
> only seems to be removing the first Parent Node, none of the children
> below
> are being cleared.
>
> Am I doing something wrong? The below code is based on retreiving data
> from
> a hierarchical table:
> Thanks,Dianna
>
>    Private Sub PopulateTreeView()
>
>        treeEvents.Nodes.Clear()
>
>        Dim cmd As String
>
>        cmd = "Select * From dbo.fncGetEventTree(null) ORDER BY lineage +
> Ltrim(Str(node,6,0))"
>
>        Dim da As New System.Data.SqlClient.SqlDataAdapter(cmd,
> ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
>
>        da.Fill(ds)
>
>        treeEvents.Nodes.Add(New TreeNode("Event Groups"))
>
>        Dim tNode As New TreeNode
>
>        tNode = treeEvents.Nodes(0)
>
>        PopulateTreeView(0, tNode)
>
>        tNode.Expand()
>    End Sub
>
>    Private Sub PopulateTreeView(ByVal inParentID As Integer, ByRef
> inTreeNode As TreeNode)
>
>        Dim newtag As String
>
>        dv = New DataView(ds.Tables(0))
>
>        dv.RowFilter = "parent_id = " & inParentID
>
>        Dim drv As DataRowView
>
>        For Each drv In dv
>
>            Dim parentnode As TreeNode
>
>            parentnode = New TreeNode(drv.Item("event"))
>
>            inTreeNode.Nodes.Add(parentnode)
>
>            parentnode.Tag = newtag
>
>            'call the routine again to find childern of this record.
>            PopulateTreeView(drv.Item("event_id"), parentnode)
>
>        Next drv
>
>    End Sub
>
>

I've tried to replicate your problem in test Windows VB apps in both Visual
Studio .NET 2003 and in Visual Studio 2005. The Clear() method clears all
nodes.
As I may have made invalid assumptions about the software you are using, its
edition and version, and I guessed at the project type and template, please
supply that information.
I may be belaboring the obvious here, but have you stepped through your
subprocedure in the debugger to see the state of the Treeview object just
after the Clear() executes?

--
Peter [MVP Visual Developer]
Jack of all trades, master of none.

4 Feb 2006 9:45 PM

Dianna

What I am noticing is that when I do
Treeview.Nodes.clear it removes the top parent to the tree ("Event Groups")
Everything else under the parent (treeEvents.Nodes(0).Nodes) - the children
stays there. Even treeview.Nodes.count says 0. However,
treeEvents.Nodes(0).Nodes.count says 17..?

It looks like I can clear the children by doing
treeEvents.Nodes(0).Nodes.Clear, but this is being built dynamically using a
hierarchical table. The user can have as many children as he wants. So the
trick will be to find out how many levels in the tree.

I think, I'm guessing.

Show quote

"pvdg42" wrote:

>
> "Dianna" <Dia***@discussions.microsoft.com> wrote in message
> news:D4C973D4-721A-4DC8-8A40-AE34E9A5CF1A@microsoft.com...
> > Hi,
> >
> > I am trying to clear my treeview when I add new items (to refresh) and It
> > only seems to be removing the first Parent Node, none of the children
> > below
> > are being cleared.
> >
> > Am I doing something wrong? The below code is based on retreiving data
> > from
> > a hierarchical table:
> > Thanks,Dianna
> >
> >    Private Sub PopulateTreeView()
> >
> >        treeEvents.Nodes.Clear()
> >
> >        Dim cmd As String
> >
> >        cmd = "Select * From dbo.fncGetEventTree(null) ORDER BY lineage +
> > Ltrim(Str(node,6,0))"
> >
> >        Dim da As New System.Data.SqlClient.SqlDataAdapter(cmd,
> > ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
> >
> >        da.Fill(ds)
> >
> >        treeEvents.Nodes.Add(New TreeNode("Event Groups"))
> >
> >        Dim tNode As New TreeNode
> >
> >        tNode = treeEvents.Nodes(0)
> >
> >        PopulateTreeView(0, tNode)
> >
> >        tNode.Expand()
> >    End Sub
> >
> >    Private Sub PopulateTreeView(ByVal inParentID As Integer, ByRef
> > inTreeNode As TreeNode)
> >
> >        Dim newtag As String
> >
> >        dv = New DataView(ds.Tables(0))
> >
> >        dv.RowFilter = "parent_id = " & inParentID
> >
> >        Dim drv As DataRowView
> >
> >        For Each drv In dv
> >
> >            Dim parentnode As TreeNode
> >
> >            parentnode = New TreeNode(drv.Item("event"))
> >
> >            inTreeNode.Nodes.Add(parentnode)
> >
> >            parentnode.Tag = newtag
> >
> >            'call the routine again to find childern of this record.
> >            PopulateTreeView(drv.Item("event_id"), parentnode)
> >
> >        Next drv
> >
> >    End Sub
> >
> >
> I've tried to replicate your problem in test Windows VB apps in both Visual
> Studio .NET 2003 and in Visual Studio 2005. The Clear() method clears all
> nodes.
> As I may have made invalid assumptions about the software you are using, its
> edition and version, and I guessed at the project type and template, please
> supply that information.
> I may be belaboring the obvious here, but have you stepped through your
> subprocedure in the debugger to see the state of the Treeview object just
> after the Clear() executes?
>
> --
> Peter [MVP Visual Developer]
> Jack of all trades, master of none.
>
>
>

4 Feb 2006 9:53 PM

Dianna

Hi Peter,

Oh Well, this was kind of dumb, but it was not the treeview. It was my
dataset. Everytime I called the routine it appened to it.

Thanks.

Dianna

Show quote

"pvdg42" wrote:

>
> "Dianna" <Dia***@discussions.microsoft.com> wrote in message
> news:D4C973D4-721A-4DC8-8A40-AE34E9A5CF1A@microsoft.com...
> > Hi,
> >
> > I am trying to clear my treeview when I add new items (to refresh) and It
> > only seems to be removing the first Parent Node, none of the children
> > below
> > are being cleared.
> >
> > Am I doing something wrong? The below code is based on retreiving data
> > from
> > a hierarchical table:
> > Thanks,Dianna
> >
> >    Private Sub PopulateTreeView()
> >
> >        treeEvents.Nodes.Clear()
> >
> >        Dim cmd As String
> >
> >        cmd = "Select * From dbo.fncGetEventTree(null) ORDER BY lineage +
> > Ltrim(Str(node,6,0))"
> >
> >        Dim da As New System.Data.SqlClient.SqlDataAdapter(cmd,
> > ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
> >
> >        da.Fill(ds)
> >
> >        treeEvents.Nodes.Add(New TreeNode("Event Groups"))
> >
> >        Dim tNode As New TreeNode
> >
> >        tNode = treeEvents.Nodes(0)
> >
> >        PopulateTreeView(0, tNode)
> >
> >        tNode.Expand()
> >    End Sub
> >
> >    Private Sub PopulateTreeView(ByVal inParentID As Integer, ByRef
> > inTreeNode As TreeNode)
> >
> >        Dim newtag As String
> >
> >        dv = New DataView(ds.Tables(0))
> >
> >        dv.RowFilter = "parent_id = " & inParentID
> >
> >        Dim drv As DataRowView
> >
> >        For Each drv In dv
> >
> >            Dim parentnode As TreeNode
> >
> >            parentnode = New TreeNode(drv.Item("event"))
> >
> >            inTreeNode.Nodes.Add(parentnode)
> >
> >            parentnode.Tag = newtag
> >
> >            'call the routine again to find childern of this record.
> >            PopulateTreeView(drv.Item("event_id"), parentnode)
> >
> >        Next drv
> >
> >    End Sub
> >
> >
> I've tried to replicate your problem in test Windows VB apps in both Visual
> Studio .NET 2003 and in Visual Studio 2005. The Clear() method clears all
> nodes.
> As I may have made invalid assumptions about the software you are using, its
> edition and version, and I guessed at the project type and template, please
> supply that information.
> I may be belaboring the obvious here, but have you stepped through your
> subprocedure in the debugger to see the state of the Treeview object just
> after the Clear() executes?
>
> --
> Peter [MVP Visual Developer]
> Jack of all trades, master of none.
>
>
>

4 Feb 2006 11:46 PM

pvdg42

"Dianna" <Dia***@discussions.microsoft.com> wrote in message
news:247A0EAB-0128-476B-8058-214B29F6B2EF@microsoft.com...
> Hi Peter,
>
> Oh Well, this was kind of dumb, but it was not the treeview. It was my
> dataset. Everytime I called the routine it appened to it.
>
> Thanks.
>
> Dianna
>

All's well that ends well :)