Get node name on treedirectory

I need to retrieve the node name according to the treeDirectory index when the Enter key is pressed
Alternative: event name at node change

private void treeDirectory_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == 13)
            {                
                int idxNode = treeDirectory.SelectedNode.Index;
                
                //How read the text of node ?


                //on Mousedouble click is possible
                //string path = pathDirectory + e.Node.FullPath + "\\";                        

                //Alternative: event name at node change
               
                //the variable  add the text of current node
                //but when node change must be erase --> pathNode = ""
                
                pathNode += treeDirectory.SelectedNode.Text + "\\";
                string path = pathDirectory + pathNode;

                //example 
                //1 - select download pathNode = "<path>\\Download\\;
                //2 - select pictures
                //3 - select A = "<path>\\Download\\A\\;</pre
                //4 - change node and select Documents 
                //I have to intercept the node change event
                ......
            }
        }