Javafx Cascading dropdown based on selection

am migrating from swing to javafx. Can anyone help with a link/code snippet on how to cascade combobox(es) based on parent-child selection in javafxe.g. country-state, branch-department-unit.

回答1:

Use this code:for basic drop down example

package comboboxexamplestackoverflow;

import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

/**
 *
 * @author reegan
 */
public class ComboBoxExampleStackOverFlow extends Application {

    @Override
    public void start(Stage primaryStage) {
        HBox box = new HBox(20);
        box.setPadding(new Insets(10, 10, 10, 10));
        ObservableList<String> countries =
                FXCollections.observableArrayList(
                "India",
                "Germany",
                "Israel");

        final ObservableList<String> indiaStates =
                FXCollections.observableArrayList(
                "StatesIndia1",
                "StatesIndia2",
                "StatesIndia3");

        final ObservableList<String> germanyStates =
                FXCollections.observableArrayList(
                "StatesGermany1",
                "StatesGermany2",
                "StatesGermany3");

        final ObservableList<String> israelStates =
                FXCollections.observableArrayList(
                "StatesIsrael1",
                "StatesIsrael2",
                "StatesIsrael3");



        ComboBox comboBox1 = new ComboBox(countries);
        final ComboBox comboBox2 = new ComboBox();
        comboBox1.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
            @Override
            public void changed(ObservableValue ov, Object t, Object t1) {

                switch (t1.toString()) {
                    case "India":
                        comboBox2.setItems(indiaStates);
                        break;
                   case "Germany":
                        comboBox2.setItems(germanyStates);
                        break;
                   case "Israel":
                        comboBox2.setItems(israelStates);
                       break;

                }
            }
        });
        box.getChildren().addAll(comboBox1, comboBox2);
        Scene scene = new Scene(box, 300, 250);

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    /**
     * The main() method is ignored in correctly deployed JavaFX application.
     * main() serves only as fallback in case the application can not be
     * launched through deployment artifacts, e.g., in IDEs with limited FX
     * support. NetBeans ignores main().
     *
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }
}

回答2:

Do it basically the same way as you would in Swing.
Use combo.getSelectionModel().selectedItemProperty().addListener() to add a ChangeListener that will be called whenever the combo box's selection changes.
See here for basic introduction to Combo Box : http://docs.oracle.com/javafx/2/ui_controls/combo-box.htm#BABJCCIB