这个

ChoiceBoxclass is used to create a control which presents the user with a few choices to pick from a drop-down list. The user is only allowed to pick one of the options. When the drop-down list is not showing then the currently selected option is the only one visible. It is possible to set the ChoiceBox

Import Statement

import javafx.scene.control.ChoiceBox;

Constructors

The ChoiceBox

Useful Methods

If you choose to create an empty ChoiceBox items can be added later using the setItems And, if you want to find out what items are in a ChoiceBox you can use the getItems To pick an option to be currently selected use the setValue To get the value of the option currently selected use the corresponding getValue method and assign it to a String String option = choices.getValue().toString(); choices.setValue("First"); List options = choices.getItems(); choices.setItems(FXCollections.observableArrayList("Apple", "Banana", "Orange", "Peach", "Pear", "Strawberry")); //Create an empty ChoiceBoxChoiceBox choices = new ChoiceBox();//Create a ChoiceBox using an observable list collectionChoiceBox cboices = new ChoiceBox(FXCollections.observableArrayList("Apple", "Banana", "Orange", "Peach", "Pear", "Strawberry"));

事件处理

为了听一段时间的事件

ChoiceBoxobject, the SelectionModelis used. The ChoiceBoxuses the SingleSelectionModelclass which only permits one option to be chosen at a time. The selectedIndexPropertymethod allows us to add a ChangeListener final List options = choices.getItems();choices.getSelectionModel().selectedIndexProperty().addListener(new ChangeListener() { @Override public void changed(ObservableValue ov, Number oldSelected, Number newSelected) { System.out.println("Old Selected Option: " + options.get(oldSelected.intValue())); System.out.println("New Selected Option: " +options.get(newSelected.intValue())); } });

还可以显示或隐藏选项列表，而无需用户单击

ChoiceBoxobject by using the showand hidemethods. In the code below a Button object is used to call the show method of a ChoiceBoxobject when the Button //Use a stackpane for a simple layout of the controlsStackPane root = new StackPane();//Create Button to show the options in the ChoiceBoxButton showOptionButton = new Button("Show Options");root.getChildren().add(showOptionButton);root.setAlignment(showOptionButton, Pos.TOP_CENTER);//Create the ChoiceBox with a few optionsfinal ChoiceBox choices = new ChoiceBox(FXCollections.observableArrayList("Apple", "Banana", "Orange", "Peach", "Pear", "Strawberry"));root.getChildren().add(choices);//Use the ActionEvent to call the ChoiceBox show methodshowOptionButton.setOnAction(new EventHandler() { @Override public void handle(ActionEvent e) { choices.show(); }});//Set the Scene and put the Stage into motion..Scene scene = new Scene(root, 300, 250);primaryStage.setScene(scene);primaryStage.show();

要了解其他JavaFX控件，请查看JavaFX用户界面控件。