How selected items from one combobox change specif

问题:

Combobox1 has 3 items (Spain, France, UK) and Combobox2 6 items (Barcelona, Madrid, Paris, Marseille, London, Bristol). When one item is selected from Combobox1 (Spain) it should be available to Combobox2 the specific items (Barcelona, Madrid).

Can anyone help me with this?

Thanks in advance

回答1:

Three combox listener example code.i think this solution use ful for your.

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package threecombobox;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
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 ThreeComboBox extends Application {

    @Override
    public void start(Stage primaryStage) {

        List combox1List = new ArrayList();
        for (int i = 1; i < 10; i++) {
            combox1List.add(i);
        }

        final Map combox2Map = new HashMap();

        for (int i = 0; i < combox1List.size(); i++) {
            List l = new ArrayList();
            for (int j = 1; j < 10; j++) {
                int k = (int) combox1List.get(i) * 10 + j;
                l.add(k);
            }
            combox2Map.put(combox1List.get(i), l);
        }
        final Map combox3Map = new HashMap();
        for (Object o : combox1List) {
            for (Object o1 : (List) combox2Map.get(o)) {
                List l = new ArrayList();
                for (int i = 1; i < 10; i++) {
                    int value = (int) o1 * 10 + i;
                    l.add(value);
                }
                combox3Map.put(o1, l);
            }
        }
        ObservableList combox1 = FXCollections.observableList(combox1List);
        HBox box = new HBox(20);
        box.setPadding(new Insets(20, 20, 20, 20));
        ComboBox cb1 = new ComboBox();
        final ComboBox cb2 = new ComboBox();
        final ComboBox cb3 = new ComboBox();
        cb1.setItems(combox1);
        cb1.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
            @Override
            public void changed(ObservableValue ov, Object t, Object t1) {
                ObservableList combox2 = FXCollections.observableArrayList((List) combox2Map.get(t1));
                cb2.setItems(combox2);
            }
        });

        cb2.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
            @Override
            public void changed(ObservableValue ov, Object t, Object t1) {
                if (t1 != null) {
                    ObservableList combox3 = FXCollections.observableArrayList((List) combox3Map.get(t1));
                    cb3.setItems(combox3);
                }
            }
        });
        box.getChildren().addAll(cb1, cb2, cb3);
        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:

Well, we don't know your data structure, but if a city is attached to a country, add a listener to your country combobox and each time the selection change, you reconfigure the items on the city combobox.

I'll do something like that :

    ComboBox<City> cityBox;
    ComboBox<Country> countryBox;

    countryBox.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
        @Override
        public void changed(ObservableValue observableValue, Country oldCountry, Country newCountry) {
            //Here configure your cityBox corresponding with newCountry
        }
    });

or with binding

    cityBox.itemsProperty().bind(new ListBinding<City>() {
        {
            bind(cityBox.getSelectionModel().selectedItemProperty());
        }
        @Override
        protected ObservableList<City> computeValue() {
            Country country = countryBox.getValue();
            // add the city corresponding to the country on a new list
            return //The list with the city filtered with the country
        }
    });