Hong Bin Han - 2020-02-20 
Option Explicit

using wxWidgets

Dim f As wxFrame
Dim m_treeCtrl As wxTreeCtrl

Sub OnItemSelectChanging(byref event As wxTreeEvent)
    Dim item As wxTreeItemId = event.GetItem()
    f.SetTitle( "treectrl demo " + m_treeCtrl.GetItemText( item ) )
End Sub

Sub Main

    f = new wxFrame( NULL, wxID_ANY, "treectrl demo" )

    Dim images As wxImageList ptr = new wxImageList(15, 15, true)   
    images.Add( wxICON(wxICON_SMALL_CLOSED_FOLDER) )
    images.Add( wxICON(wxICON_SMALL_OPEN_FOLDER) )
    images.Add( wxICON(wxICON_SMALL_FILE) )

    m_treeCtrl = new wxTreeCtrl(f, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxTR_DEFAULT_STYLE)
    m_treeCtrl.SetImageList( images )

    Dim root As wxTreeItemId = m_treeCtrl.AppendItem( NULL, "root", 0, 1 )
    m_treeCtrl.AppendItem( root, "item1", 2 )
    m_treeCtrl.AppendItem( root, "item2", 2 )
    m_treeCtrl.AppendItem( root, "item3", 2 )
    m_treeCtrl.AppendItem( root, "item4", 2 )
    m_treeCtrl.AppendItem( root, "item5", 2 )

    m_treeCtrl.Bind( wxEVT_TREE_SEL_CHANGING, AddressOf OnItemSelectChanging )

    f.SetIcon( wxICON(wxICON_AAA) )
    f.Show(true)

End Sub