Can I get the index of an inserted node in a treeview?

Question

In my treeview I want to remember which nodes were expanded and redraw that state after I delete or insert a node. I solved that with remembering the index of an expanded node. If a node is removed, I decrement all indeces that were afterwards. That works because I can access the deleted node with treeView.SelectedNode, but how can I get the new Index of the inserted node? I can not solve it with saving a reference to the node or a name or a tag, because when I redraw the tree the nodes are created completely new - and I think I can not get a reference to the newly created node anyway Best regards, Expecto

score 0 · Answer 1 · answered Jul 31 '12 at 07:53

0

My way: use your own declared class:

class TreeNodeEx : TreeNode
{
    public void Remove()
    {
        base.Remove();
        // what you want to do
        UpdateNode(this.Parent);
    }
}

answered Jul 31 '12 at 07:53

Ria

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score 0 · Answer 2 · answered Jul 31 '12 at 08:52

You could bind an observableCollection to your TreeNode Then :

        var obd =  Observable.FromEvent<NotifyCollectionChangedEventArgs>(
            ev => obdCollection.CollectionChanged += CheckChanges,ev=> obdCollection.CollectionChanged -= CheckChanges);


   private void CheckChanges(object sender, NotifyCollectionChangedEventArgs e)
    {
        Console.WriteLine("new Starting index : "+e.NewStartingIndex);
        Console.WriteLine("Old Starting index : " + e.OldStartingIndex);
        Console.WriteLine("new Items : " + e.NewItems);
        Console.WriteLine("Old Items : " + e.OldItems);


    }

That way you can check what has changed in the collection.

score 0 · Accepted Answer · answered Aug 01 '12 at 11:52

The answers were not really what I was looking for, but after I found out that after an insert the "AfterSelect" Event fires, I did it this way:

private void treeViewProduct_AfterSelect(object sender, TreeViewEventArgs e)
    {

        if (insertMode)
        {

            treeViewProduct.NotifyAboutInsert(e.Node.Index);
        }
...
}

My treeview then handles the changed indices for the nodes after that and perfectly redraws the tree.

Can I get the index of an inserted node in a treeview?

3 Answers3