In the tdxtreelist control, how does one determine whether the checkpoint title has been selected or canceled?

In the tdxtreelist control, how does one determine whether the checkpoint title has been selected or canceled? Development and Application of VCL Components
Http://www.delphi2007.net/DelphiVCL/html/delphi_20061225101425137.html
I added a tdxtreelistcheckcolumn IN THE tdxtreelist control, but it is always true when determining whether to select it in the title event, Code As follows:
Procedure tform1.coifcheckedtoggleclick (Sender: tobject;
Const text: string; State: tdxcheckboxstate );
VaR
Lcnode: tdxtreelistnode;
Lbselect: Boolean;
Begin
Lcnode: = dxtreelist. focusednode;
If assigned (lcnode) then
Begin
Lbselect: = lcnode. Values [coifchecked. Index];
If lbselect then
Showmessage ('true ')
Else showmessage ('false ');
End;
End;