My code:

New line:

TLNode tln1 = new TLNode(1, treeList1.Nodes, new_item.Name_Link.Text, new_item.Link.Text);
treeList1.Nodes.Add(tln1);

This is new folder:

TLNode tln1 = new TLNode(1, treeList1.Nodes, new_folder.textEdit_New_Folder.Text, "");
tln1.HasChildren = true;
TLNode tln_children = new TLNode(2, tln1.Nodes, "", "");
tln1.Nodes.Add(tln_children);
treeList1.Nodes.Add(tln1);

If TreeList hot have folder - Ok! (new node can have focus)
If TreeList have folder and it is close - Ok! (new node can have focus)
If TreeList have open folder - new line in TreeList not can have focus.

Help me please!