如何从常规类访问控制器类的字段？

Question

我正在使用 JavaFX 通过 Gluon 框架创建 Android/Iphone 应用程序。我知道这种类型的“我怎样才能获得控制器类”的问题。但这是不同的。我知道如何获得控制器类，但这不是我要求的。我问如何在不创建任何新对象的情况下从控制器类访问字段。假设我们有一个这样的 JavaFX 控制器类：public class PrimaryPresenter {    @FXML    private View primary;    @FXML    public LineChart<String, Number> lineChart; // Every time we update the socket, we update the chart too    public void initialize() {        primary.setShowTransitionFactory(BounceInRightTransition::new);        primary.showingProperty().addListener((obs, oldValue, newValue) -> {            if (newValue) {                AppBar appBar = MobileApplication.getInstance().getAppBar();                appBar.setNavIcon(MaterialDesignIcon.MENU.button(e ->                         MobileApplication.getInstance().getDrawer().open()));                appBar.setTitleText("Plot");            }        });           /*         * Initial stuffs for the lineChart         */        lineChart.setTitle("Adaptive MPC");    }}我想lineChart从另一个类访问对象而不创建新的PrimaryPresenter控制器类。FXML 文件由 Scene Builder 创建。我问这个问题的原因是因为我有另一个通过线程循环的类，并且该线程将lineChart实时更新对象。

Answer 1

这是我的答案。在每个 Gluon 项目中，都有一个名为的类GluonApplication，它看起来像这样：

package com.gluonapplication;

import com.gluonapplication.thread.SocketConnection;

import com.gluonapplication.views.PrimaryView;

import com.gluonapplication.views.SecondaryView;

import com.gluonhq.charm.glisten.application.MobileApplication;

import com.gluonhq.charm.glisten.visual.Swatch;

import javafx.scene.Scene;

import javafx.scene.image.Image;

import javafx.stage.Stage;

public class GluonApplication extends MobileApplication {

    public static final String PRIMARY_VIEW = HOME_VIEW;

    public static final String SECONDARY_VIEW = "Secondary View";

    @Override

    public void init() {

        addViewFactory(PRIMARY_VIEW, () -> new PrimaryView().getView());

        addViewFactory(SECONDARY_VIEW, () -> new SecondaryView().getView());

        DrawerManager.buildDrawer(this);

    }

    @Override

    public void postInit(Scene scene) {

        Swatch.GREEN.assignTo(scene);

        scene.getStylesheets().add(GluonApplication.class.getResource("style.css").toExternalForm());

        ((Stage) scene.getWindow()).getIcons().add(new Image(GluonApplication.class.getResourceAsStream("/icon2.png")));

    }

}

可以访问控制器类中的所有字段。只需这样做：

public class GluonApplication extends MobileApplication {

    public static final String PRIMARY_VIEW = HOME_VIEW;

    public static final String SECONDARY_VIEW = "Secondary View";

    private SocketConnection socketConnection;

    private View primaryView; // Add

    private View secondaryView; // Add

    @Override

    public void init() {

        primaryView = new PrimaryView().getView();

        secondaryView = new SecondaryView().getView();

        addViewFactory(PRIMARY_VIEW, () -> primaryView);

        addViewFactory(SECONDARY_VIEW, () -> secondaryView);

        DrawerManager.buildDrawer(this);

        /*

         * This will start the socket connection

         */

        socketConnection = new SocketConnection(primaryView, secondaryView);

        socketConnection.start();

    }

    @Override

    public void postInit(Scene scene) {

        Swatch.GREEN.assignTo(scene);

        scene.getStylesheets().add(GluonApplication.class.getResource("style.css").toExternalForm());

        ((Stage) scene.getWindow()).getIcons().add(new Image(GluonApplication.class.getResourceAsStream("/icon2.png")));

    }

}

然后在SocketConnection的构造函数中。您可以像这样访问字段：

    /*

     * Constructor

     */

    public SocketConnection(View primaryView, View secondaryView) {

        /*

         * For secondaryView

         */

        statusTextField = (TextField) secondaryView.lookup("#statusTextField");

        ipAddressTextField = (TextField) secondaryView.lookup("#ipAddressTextField");

        startSignalModeComboBox = (ComboBox<String>) secondaryView.lookup("#startSignalModeComboBox");

        predictHorizonTextField = (TextField) secondaryView.lookup("#predictHorizonTextField");

        controlHorizonTextField = (TextField) secondaryView.lookup("#controlHorizonTextField");

        sampleTimeTextField = (TextField) secondaryView.lookup("#sampleTimeTextField");

        pwmDutyCallTextField = (TextField) secondaryView.lookup("#pwmDutyCallTextField");

        endTimeOfStartSignalTextField = (TextField) secondaryView.lookup("#endTimeOfStartSignalTextField");

        referencePointTextField = (TextField) secondaryView.lookup("#referencePointTextField");

        portTextField = (TextField) secondaryView.lookup("#portTextField");

        /*

         * For primaryView

         */

        lineChart = (LineChart<String, Number>) primaryView.lookup("#lineChart");

        /*

         * Declare the data object inside the chart

         */

        time_output = new Series<String, Number>();

        lineChart.getData().add(time_output);

    }