JavaFx之场景交互（二十一）

有parent、son两个父子窗口，父窗口可以操作子窗口，父子可以相互调用对方的对象，下面我给出两种方案，我推荐使用第二种

一、构造传参

参数比较多的话代码不优雅、而且不太方便维护。
父

package top.oneit.jdownload.test;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.AnchorPane;
import javafx.stage.Stage;

/**
 * @author lingkang
 */
public class MyParent extends Application {
    private MySonA sonA;
    private Button button;

    @Override
    public void start(Stage primaryStage) throws Exception {
        button = new Button("open子窗口A");
        button.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                if (sonA==null){
                    sonA = new MySonA(primaryStage,button);
                    sonA.show();// 显示子窗口
                }else{
                    sonA.show();
                }
                // 调用子接口对象
                System.out.println(sonA.getButton().getText());
            }
        });

        Button closeSon = new Button("关闭子窗口");
        closeSon.setLayoutY(40);
        closeSon.setOnAction(event -> {
            sonA.close();
        });

        AnchorPane anchorPane = new AnchorPane(button, closeSon);
        anchorPane.setPrefWidth(400);
        anchorPane.setPrefHeight(300);
        primaryStage.setScene(new Scene(anchorPane));
        primaryStage.show();
    }

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

子

package top.oneit.jdownload.test;

import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.AnchorPane;
import javafx.stage.Stage;

/**
 * @author lingkang
 */
public class MySonA extends Stage {
    private Stage parent;
    private Button button;

    public MySonA(Stage parent,Button parentButton) {
        this.parent = parent;
        Label label = new Label("我是儿子A");
        button = new Button("关闭父窗口");
        button.setOnAction(event -> {
            System.out.println(parent.getTitle());
            parent.close();
        });
        button.setLayoutY(40);

        Button open = new Button("打开父窗口");
        open.setLayoutY(80);
        open.setOnAction(event -> {
            parentButton.setText("子调用父的对象");// 父子传参，构造方法
            parent.show();
        });

        Button exit = new Button("exit");
        exit.setLayoutY(120);
        exit.setOnAction(event -> {
            System.exit(0);
        });

        AnchorPane pane = new AnchorPane(label, button, open, exit);
        pane.setPrefWidth(300);
        pane.setPrefHeight(200);
        setScene(new Scene(pane));
    }

    public Button getButton() {
        return button;
    }

    public void setButton(Button button) {
        this.button = button;
    }
}

效果：

二、继承公共类

灵活，注意，创建多个同样的窗口带来的问题，还有获取对应stage为空的问题！提前判空
启动入口

import javafx.application.Application;
import javafx.stage.Stage;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * @author lingkang
 * @date 2021/11/18
 */
public class MyApp extends Application {
    public static ConcurrentMap<String, Stage> stages = new ConcurrentHashMap<>();

    @Override
    public void start(Stage primaryStage) throws Exception {
        new MyParent();//显示父窗口
    }

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

公共类

import javafx.event.EventHandler;
import javafx.stage.Stage;
import javafx.stage.WindowEvent;

/**
 * @author lingkang
 * @date 2021/11/18
 */
public class MyStageCommon extends Stage {

    public MyStageCommon() {
        super();
        // 创建窗口时加入
        MyApp.stages.put(getClass().getName(), this);
        // x 掉窗口时将它移除
        setOnCloseRequest(new EventHandler<WindowEvent>() {
            @Override
            public void handle(WindowEvent event) {
                MyApp.stages.remove(getClass().getName());
            }
        });
    }

    @Override
    public void close() {
        super.close();
        MyApp.stages.remove(getClass().getName());
    }

    /**
     * 获取对象,,注意返回空值
     */
    public <T> T getStage(Class<T> clazz) {
        Stage stage = MyApp.stages.get(clazz.getName());
        if (stage == null)
            return null;
        return (T) MyApp.stages.get(clazz.getName());
    }
}

父

import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.AnchorPane;

/**
 * @author lingkang
 */
public class MyParent extends MyStageCommon {
    public Button button;

    public MyParent() {
        setTitle("父窗口！");
        button = new Button("open子窗口A");
        button.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                if (getStage(MySonA.class) == null) {
                    new MySonA().show();// 显示子窗口
                } else {
                    getStage(MySonA.class).show();
                }
                // 调用子接口对象
                System.out.println(getStage(MySonA.class).button.getText());
            }
        });

        Button closeSon = new Button("关闭子窗口");
        closeSon.setLayoutY(40);
        closeSon.setOnAction(event -> {
            if (getStage(MySonA.class) != null)
                getStage(MySonA.class).close();
        });

        AnchorPane anchorPane = new AnchorPane(button, closeSon);
        anchorPane.setPrefWidth(400);
        anchorPane.setPrefHeight(300);
        setScene(new Scene(anchorPane));
        show();
    }
}

子

import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.AnchorPane;

import java.util.Date;

/**
 * @author lingkang
 */
public class MySonA extends MyStageCommon {
    public Button button;

    public MySonA() {
        setTitle("子窗口A");
        MyParent parent = getStage(MyParent.class);
        Label label = new Label("我是儿子A");
        button = new Button("关闭父窗口");
        button.setOnAction(event -> {
            System.out.println(parent.getTitle());
            parent.close();
        });
        button.setLayoutY(40);

        Button open = new Button("打开父窗口");
        open.setLayoutY(80);
        open.setOnAction(event -> {
            if (parent.button != null)
                parent.button.setText("子调用父的对象" + new Date());// 父子传参
            parent.show();
        });

        Button exit = new Button("exit");
        exit.setLayoutY(120);
        exit.setOnAction(event -> {
            System.exit(0);
        });

        AnchorPane pane = new AnchorPane(label, button, open, exit);
        pane.setPrefWidth(300);
        pane.setPrefHeight(200);
        setScene(new Scene(pane));
    }
}

效果：