Question

我昨天在JavaFX中构建了一个小应用程序。我想在Controller类中获取应用程序的场景。每次我尝试在控制器类中获取场景时都会出错。我可以在Controller类的Button上设置OnKeyPressed方法，工作正常。但是如果选择了Button，它的工作正常。我只能在Main-class方法replaceSceneContent中获取场景。我读过this question already，但是我在initialize-method中调用了getScene（）方法？谢谢你的任何想法！

主要课程：

public class Main extends Application {

private Stage stage;

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

@Override
public void start(Stage primaryStage) throws Exception {
    stage = primaryStage;
    gotoMenu();
    primaryStage.show();
}

public void gotoMenu() {
    try {
        MenuController menu = new MenuController();
        menu = (MenuController) replaceSceneContent("Menu.fxml");
        menu.setApp(this);
    } catch (Exception ex) {
        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
    }
}

private Node replaceSceneContent(String fxml) throws Exception {
    FXMLLoader loader = new FXMLLoader();
    @SuppressWarnings("resource")
    InputStream in = Main.class.getResourceAsStream(fxml);
    loader.setBuilderFactory(new JavaFXBuilderFactory());
    loader.setLocation(Main.class.getResource(fxml));
    BorderPane page;
    try {
        page = (BorderPane) loader.load(in);
    } finally {
        in.close();
    }
    page.setOnKeyPressed(event -> {
        switch (event.getCode()) {
        case F11:
            if (stage.isFullScreen()) {
                stage.setFullScreen(false);
            } else {
                stage.setFullScreen(true);
            }
            break;
        default:
            break;
        }
    });
    Scene scene = new Scene(page);
    page.prefWidthProperty().bind(scene.widthProperty());
    page.prefHeightProperty().bind(scene.heightProperty());
    stage.setScene(scene);
    return (Node) loader.getController();
}}

控制器类：

public class MenuController extends BorderPane implements Initializable {

Main application;

@FXML
private Button button;

public void setApp (Main application) {
    this.application = application;
}

@Override
public void initialize(URL location, ResourceBundle resources) {
    button.getScene().setOnKeyPressed(e -> {
        switch(e.getCode()) {
        case A:
            System.out.println("A pressed!");
            break;
        default:
            break;
        }
    });
}}}

Answer 1

这是我的应用程序的1.1版本。我在setOnKeyPressed事件处理程序中添加了一个if子句。控制器初始化完成后，方法将布尔控制器运行转为true。最后我删除了InputStream，不需要它。

如果有人需要一个例子：

主要课程：

public class Main extends Application {

private Stage stage;
private boolean controllerRunning = false;
MenuController menu;

public void setControllerRunning(boolean controllerRunning) {
    this.controllerRunning = controllerRunning;
}

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

@Override
public void start(Stage primaryStage) throws Exception {
    stage = primaryStage;
    gotoMenu();
    primaryStage.show();
}

public void gotoMenu() {
    try {
        menu = new MenuController();
        menu = (MenuController) replaceSceneContent("Menu.fxml");
        menu.setApp(this);
        menu.keyFunctions();
    } catch (Exception ex) {
        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
    }
}

private Node replaceSceneContent(String fxml) throws Exception {
    FXMLLoader loader = new FXMLLoader();
    loader.setBuilderFactory(new JavaFXBuilderFactory());
    loader.setLocation(Main.class.getResource(fxml));
    BorderPane page;
    try {
        page = (BorderPane) loader.load();
    } finally {
    }
    page.setOnKeyPressed(event -> {
        if (controllerRunning) {
            switch (event.getCode()) {
            case A:
                menu.printA();
                break;
            default:
                break;
            }
        }
        switch (event.getCode()) {
        case F11:
            if (stage.isFullScreen()) {
                stage.setFullScreen(false);
            } else {
                stage.setFullScreen(true);
            }
            break;
        default:
            break;
        }
    });
    Scene scene = new Scene(page);
    page.prefWidthProperty().bind(scene.widthProperty());
    page.prefHeightProperty().bind(scene.heightProperty());
    stage.setScene(scene);
    return (Node) loader.getController();
}}

控制器类：

public class MenuController extends BorderPane{

Main application;

@FXML
private Button button;

public void setApp (Main application) {
    this.application = application;
}

public void keyFunctions() {
    application.setControllerRunning(true);
}
public void printA() {
    System.out.println("A!");
}
}

Answer 2

你可以做到

private Node replaceSceneContent(String fxml) throws Exception {
    FXMLLoader loader = new FXMLLoader();
    loader.setBuilderFactory(new JavaFXBuilderFactory());
    loader.setLocation(Main.class.getResource(fxml));

    BorderPane page = loader.load();
    MenuController controller = loader.getController();

    page.setOnKeyPressed(event -> {
        switch (event.getCode()) {
        case F11:
            if (stage.isFullScreen()) {
                stage.setFullScreen(false);
            } else {
                stage.setFullScreen(true);
            }
            break;
        default:
            break;
        }
    });
    Scene scene = new Scene(page);
    scene.setOnKeyPressed(event -> {
        if (event.getCode() == KeyCode.A) {
            controller.printA();
        }
    });


    page.prefWidthProperty().bind(scene.widthProperty());
    page.prefHeightProperty().bind(scene.heightProperty());
    stage.setScene(scene);
    return controller ;
}

与

public class MenuController extends BorderPane{

    // existing code...

    public void printA() {
        System.out.println("A!");
    }

}

只是评论：MenuController成为BorderPane（或任何其他UI类）的子类绝对没有意义。我把它留在了其他地方，如果你需要它，但它完全违反了MVC模式。

此外，我不确定为什么你希望A的密钥处理程序在场景中，而 F11 的密钥处理程序在场景的根目录上。看来这些都应该在场景中注册。但是，我再次将其留在了问题中。

JavaFX getScene（）在控制器

2 个答案: