javafx data transfer between dialogs

There are two dialogs. How to transfer any value from dialog2 to dialog1 : I try this: In dialog 1:

public void setCategory(String kateg) { System.out.println(kateg); pmk_id.setText(kateg); } 

in dialogue 2:

 public void kategTreeMouseClick(MouseEvent mouseEvent) { int click = mouseEvent.getClickCount(); if (click == 2) { TreeItem<pmk_category> kateg =kategTree.getSelectionModel().getSelectedItem(); addToPMKController addCategory = new addToPMKController(); addCategory.setCategory(kateg.getValue().getCategory()); dialogStage.close(); } } 

As a result, the value is passed, but not displayed in the TextField , although in System.out.println(kateg); I see the transmitted value.

Tell me what's wrong.