Java 存在'；这是一个适当的价值观

我遇到的问题是，用户名不会显示在我的游说窗格中。我使用了System.out.println（MainStart.player.getName（））；验证名称是否存在并获取正确信息。由于某种原因，它不会显示。为了尽我所能简化本例中的大量代码，例如导入和设计。这是我的问题的一个简短形式

每个窗格中都有相应的场景，这些场景都在进行场景切换，但是它们都只有几行代码，所以我将它们省略了

主流艺术

public class MainStart extends Application {

    public static Stage mainStage;
    public static int sceneWidth = 1050;
    public static int sceneHeight = 600;
    public static Character player = new Character();
    private static IntroScene introScene = new IntroScene();
    private static NewPlayerScene newPlayerScene = new NewPlayerScene();
    private static LobbyScene lobbyScene = new LobbyScene();

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

    @Override
    public void start(Stage primaryStage) throws Exception {
        mainStage = primaryStage;
        mainStage.setTitle("game");
        mainStage.setResizable(false);
        mainStage.show();
        setScene("introScene");
    }

    public static void setScene(String scene) {

        switch (scene){
            case "introScene":
                mainStage.setScene(introScene);
                break;
            case "newPlayerScene":
                mainStage.setScene(newPlayerScene);
                break;
            case "lobbyScene":
                mainStage.setScene(lobbyScene);
                break;
        }
    }
}

内窗格

public class IntroPane extends VBox {

    public IntroPane() {
        /* Main VBox */
        this.getChildren().addAll(titleText, buttons());
        this.setAlignment(Pos.CENTER);
        this.setSpacing(80);
    }

    public HBox buttons(){
        HBox buttons = new HBox();
        /* New Game Button */
        Button newGame = new Button("New Game");
        MyStyles.ButtonStyle(newGame);
        newGame.setOnMouseClicked(e->{
            MainStart.setScene("newPlayerScene");
        });

        /* Add buttons to HBox */
        buttons.getChildren().addAll(newGame);
        buttons.setSpacing(100);
        buttons.setAlignment(Pos.CENTER);
        return buttons;
    }
}

新柏油烷

public class NewPlayerPane extends VBox {

    private TextField userName = new TextField();

    public NewPlayerPane() {
        /* User Input */
        userName.setMaxWidth(400);
        /* Press Enter */
        userName.setOnKeyPressed(new EventHandler<KeyEvent>() {
            @Override
            public void handle(KeyEvent keyEvent) {
                if (keyEvent.getCode() == KeyCode.ENTER) {
                    send();
                }
            }
        });

        /* Buttons */
        Button submit = new Button("Submit");
        MyStyles.ButtonStyle(submit);
        submit.setOnAction(e->{
            send();
        });

        /* Button HBox */
        HBox buttons = new HBox(50);
        buttons.getChildren().addAll(submit);
        buttons.setAlignment(Pos.CENTER);

        /* Set */
        this.setSpacing(50);
        this.setAlignment(Pos.CENTER);
        this.getChildren().addAll(enterName, userName, buttons);
    }

    public void send() {
        String userNameText = userName.getText();
        MainStart.player.setName(userNameText);
        userName.setText("");
        MainStart.setScene("lobbyScene");
    }
}

性格

public class Character {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
        System.out.println(name);
    }
}

---

哪一行正在打印null？LobbyPane/*Name/Text userName=新文本（MainStart.player.getName（））；/VBox*/VBox top=新的VBox（）；top.getChildren（）.addAll（用户名）；返回顶部；哪一行正在打印null？LobbyPane/*Name/Text userName=新文本（MainStart.player.getName（））；/VBox*/VBox top=新的VBox（）；top.getChildren（）.addAll（用户名）；返回顶部；

public class Character {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
        System.out.println(name);
    }
}