在 JavaFX 中更新对象状态更改的 UI 节点的正确方法是什么？

Question

有一个名为播放器的java类，如下所示：public class Player {    private String playerName;    private int score;    public Player(String playerName) {        this.playerName = playerName;        this.score = 0;    }    public void incrementScore(int by) {        this.score+=by;    }    public String getPlayerName() {        return this.playerName;    }}我只是想知道，一旦 Player 实例更改其分数，哪种正确方法可以更新 UI，例如提供的 UI：public class PlayerUI extends Application {    public static void main(String[] args) {        launch();    }    @Override    public void start(Stage primaryStage) throws Exception {        Player player = new Player("Mario");        VBox box = new VBox();        box.setSpacing(20.);        box.setPadding(new Insets(20.));        Text playerName = new Text("Player: " + player.getPlayerName());        Text score = new Text("Score: " + player.getPlayerScore());        Button incrementScore = new Button("Score up");        incrementScore.setOnAction(new IncrementScoreHandler(player, score));        box.getChildren().add(playerName);        box.getChildren().add(score);        box.getChildren().add(incrementScore);        Scene mainScene = new Scene(box);        primaryStage.setScene(mainScene);        primaryStage.setResizable(false);        primaryStage.show();    }}我使用事件处理程序执行此操作，该处理程序将播放器和所涉及的节点作为构造函数中的参数接收。public class IncrementScoreHandler implements EventHandler<ActionEvent> {    private Player player;    private Text scoreText;    public IncrementScoreHandler(Player player, Text score) {        this.player = player;        this.scoreText = score;    }    @Override    public void handle(ActionEvent event) {        player.incrementScore(1);        this.scoreText.setText("Score: " + player.getPlayerScore());    }}它是正确的吗？重构、让和得分更好吗？PlayerplayerNameStringPropertyIntegerProperty

Answer 1

是的，您可能希望重构类以改用可观察属性。Player

然后，只需将节点（或以下示例中的节点）绑定到这些属性即可。TextLabel

import javafx.application.Application;

import javafx.beans.property.IntegerProperty;

import javafx.beans.property.SimpleIntegerProperty;

import javafx.beans.property.SimpleStringProperty;

import javafx.beans.property.StringProperty;

import javafx.geometry.Insets;

import javafx.geometry.Pos;

import javafx.scene.Scene;

import javafx.scene.control.Button;

import javafx.scene.control.Label;

import javafx.scene.layout.GridPane;

import javafx.scene.layout.VBox;

import javafx.stage.Stage;

public class PropertiesExample extends Application {

    public static void main(String[] args) {

        launch(args);

    }

    @Override

    public void start(Stage primaryStage) {

        // Simple interface

        VBox root = new VBox(5);

        root.setPadding(new Insets(10));

        root.setAlignment(Pos.CENTER);

        // Create our Player

        Player player = new Player("Mario");

        // For this example, a simple GridPane will hold our nodes

        GridPane gridPane = new GridPane();

        // Add our data headers

        gridPane.add(new Label("Player:"), 0, 0);

        gridPane.add(new Label("Score:"), 0, 1);

        // Our labels to hold the changeable data

        Label lblPlayerName = new Label();

        Label lblPlayerScore = new Label();

        gridPane.add(lblPlayerName, 1, 0);

        gridPane.add(lblPlayerScore, 1, 1);

        // Use the Player properties to bind our displayed values to the Labels

        lblPlayerName.textProperty().bind(player.playerNameProperty());

        lblPlayerScore.textProperty().bind(player.scoreProperty().asString());

        Button btnIncrementScore = new Button("Score Up");

        btnIncrementScore.setOnAction(event -> player.incrementScore());

        root.getChildren().addAll(gridPane, btnIncrementScore);

        // Show the Stage

        primaryStage.setWidth(300);

        primaryStage.setHeight(300);

        primaryStage.setScene(new Scene(root));

        primaryStage.show();

    }

}