JavaFX ChoiceBox

Jakob Jenkov
Last update: 2020-12-14

The JavaFX ChoiceBox control enables users to choose an option from a predefined list of choices. The JavaFX ChoiceBox control is represented by the class javafx.scene.control.ChoiceBox . This JavaFX ChoiceBox tutorial will explain how to use the ChoiceBox class.

Creating a ChoiceBox

You create a ChoiceBox simply by creating a new instance of the ChoiceBox class. Here is a JavaFX ChoiceBox instantiation example:

ChoiceBox choiceBox = new ChoiceBox();

Adding Choices to a ChoiceBox

You can add choices to a ChoiceBox by obtaining its item collection and add items to it. Here is an example that adds choices to a JavaFX ChoiceBox :

choiceBox.getItems().add("Choice 1");
choiceBox.getItems().add("Choice 2");
choiceBox.getItems().add("Choice 3");

Adding a ChoiceBox to the Scene Graph

To make a ChoiceBox visible you must add it to the scene graph. This means that you must add the ChoiceBox to a Scene object or to some layout component which is then attached to the Scene object.

Here is an example showing how to add a JavaFX ChoiceBox to the scene graph:

package com.jenkov.javafx.controls;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.ChoiceBox;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class ChoiceBoxExperiments extends Application  {

    @Override
    public void start(Stage primaryStage) throws Exception {
        primaryStage.setTitle("ChoiceBox Experiment 1");

        ChoiceBox choiceBox = new ChoiceBox();

        choiceBox.getItems().add("Choice 1");
        choiceBox.getItems().add("Choice 2");
        choiceBox.getItems().add("Choice 3");

        HBox hbox = new HBox(choiceBox);

        Scene scene = new Scene(hbox, 200, 100);
        primaryStage.setScene(scene);
        primaryStage.show();

    }

    public static void main(String[] args) {
        Application.launch(args);
    }
}

The application resulting from running this example would look similar to this:

A JavaFX ChoiceBox displayed via the scene graph

Reading the Selected Value

You can read the selected value of a ChoiceBox via its getValue() method. If no choice is selected, the getValue() method returns null. Here is an example of calling getValue():

String value = (String) choiceBox.getValue();

Listening for Selection

It is possible to listen for selection changes in a JavaFX ChoiceBox by setting an action listener on the ChoiceBox via its setOnAction() method. Here is an example of setting an action listener on a ChoiceBox which reads what value was selected in the ChoiceBox:

ChoiceBox choiceBox = new ChoiceBox();

choiceBox.getItems().add("Choice 1");
choiceBox.getItems().add("Choice 2");
choiceBox.getItems().add("Choice 3");

choiceBox.setOnAction((event) -> {
    int selectedIndex = choiceBox.getSelectionModel().getSelectedIndex();
    Object selectedItem = choiceBox.getSelectionModel().getSelectedItem();

    System.out.println("Selection made: [" + selectedIndex + "] " + selectedItem);
    System.out.println("   ChoiceBox.getValue(): " + choiceBox.getValue());
});

Jakob Jenkov

Featured Videos




















Advertisements

High-Performance
Java Persistence
Close TOC
All Tutorial Trails
All Trails
Table of contents (TOC) for this tutorial trail
Trail TOC
Table of contents (TOC) for this tutorial
Page TOC
Previous tutorial in this tutorial trail
Previous
Next tutorial in this tutorial trail
Next