Select the first leaf node of a tree

[Nataraj Vedula]

Hi,

I have a Rad tree view bound to a dataset. When page loads, i want to display the tree view with the first leaf node in the tree structure. for Eg:
Consider tree has the following structure:
A:-
    A1:-
        A11:-
            A111
            A112
            A113
        A12:-
            A121
            A122
        A13
    A2:-
        A21:-
            A211
            A212:-
                A2121
        A22
    A3
B:-
    B1:-
    so on...

when page loads i want to show the user node A11 selected and also parent nodes for A11 expanded.(if A11 has no child nodes then A11 has to be selected as it will be first leaf node) How can i do this server side?

I tried to do it by loops but i am not successful to traverse through the nodes at diefferent levels.

Please help me.

Thanks in advance,
Nataraj

[Simon]

Hello Nataraj Vedula,

You can use the following routines to achieve your goal:

[C#]

private void LocateFirstLeafNode()
{
    RadTreeNode node = GetFirstLeafNode(this.RadTreeView1.Nodes);

    if (node != null)
    {
        node.Selected = true;

        node.ExpandParentNodes();
    }
}

private RadTreeNode GetFirstLeafNode(RadTreeNodeCollection nodes)
{
    RadTreeNode firstLeafNode = null;

    if (nodes.Count > 0)
    {
        if (nodes[0].Nodes.Count == 0)
        {
            firstLeafNode = nodes[0];
        }
        else
        {
            firstLeafNode = GetFirstLeafNode(nodes[0].Nodes);
        }
    }

    return firstLeafNode;
}

[VB.NET]

Private Sub LocateFirstLeafNode()
    Dim node As RadTreeNode = GetFirstLeafNode(Me.RadTreeView1.Nodes)

    If node IsNot Nothing Then
        node.Selected = True

        node.ExpandParentNodes()
    End If
End Sub

Private Function GetFirstLeafNode(ByVal nodes As RadTreeNodeCollection) As RadTreeNode
    Dim firstLeafNode As RadTreeNode = Nothing

    If nodes.Count > 0 Then
        If nodes(0).Nodes.Count = 0 Then
            firstLeafNode = nodes(0)
        Else
            firstLeafNode = GetFirstLeafNode(nodes(0).Nodes)
        End If
    End If

    Return firstLeafNode
End Function

I hope this is useful.

Best wishes,
Simon
the Telerik team

Check out Telerik Trainer, the state of the art learning tool for Telerik products.

[Nataraj Vedula]

It works great. Thanks Simon.

Regards,
Nataraj