javafx - CheckComboBox choices are empty -

hi learning javafx , want create dropdown multiple select. think need use checkcombobox. implement did no show elements. here`s code:

in fxml : <checkcombobox fx:id="keywordbox" layoutx="233.0" layouty="240.0" prefheight="25.0" prefwidth="131.0" />

in controller:

@override public void initialize(url location, resourcebundle resources) {     final observablelist<string> strings = fxcollections.observablearraylist();      (int = 0; <= 4; i++) {          strings.add("item " + i);      } keywordbox = new checkcombobox<string>(strings);  keywordbox.getcheckmodel().getcheckeditems().addlistener(new listchangelistener<string>() {      public void onchanged(listchangelistener.change<? extends string> c) {          system.out.println(keywordbox.getcheckmodel().getcheckeditems());      }      }); } 

and dropdown empty. idea?

you creating new checkcombobox instead of using 1 fxml.

remove line:

keywordbox = new checkcombobox<string>(strings); 

and add items model of existing keywordbox.