如何显示关闭 JavaFX 程序的退出按钮？

Question

我一直在尝试在java中的这个程序中添加一个按钮，显示“退出”，然后关闭该程序。给出的程序制作并显示了火箭的图像，所以我不能使用另一个名为

QuitButtonExample.java

的程序给我的示例，因为每个程序都有不同的东西，并且在

QuitButtonExample

中使用类似的结构

 如果我删除了两部分代码，则只允许我显示火箭图像或退出按钮。以下为

Rocket.java

正常程序供参考。

Rocket.java：

Rocket.java我使用了

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Polygon;
import javafx.scene.shape.Polyline;
import javafx.stage.Stage;

public class Rocket extends Application
{
   //--------------------------------------------------------------------
   //  Displays a rocket lifting off. The rocket and hatch are polygons
   //  and the flame is a polyline.
   //--------------------------------------------------------------------
   public void start(Stage primaryStage)
   {
   double[] hullPoints = {200, 25, 240, 60, 240, 230, 270, 260, 
            270, 300, 140, 300, 140, 260, 160, 230, 160, 60};
      Polygon rocket = new Polygon(hullPoints);
      rocket.setFill(Color.BEIGE);
      double[] hatchPoints = {185, 70, 215, 70, 220, 120, 180, 120};

      Polygon hatch = new Polygon(hatchPoints);
      hatch.setFill(Color.MAROON);

      double[] flamePoints = {142, 310, 142, 330, 150, 325, 155, 380, 
               165, 340, 175, 360, 190, 350, 200, 375, 215, 330, 220, 360, 
               225, 355, 230, 370, 240, 340, 255, 370, 260, 335, 268, 340, 
               268, 310};

      Polyline flame = new Polyline(flamePoints);
      flame.setStroke(Color.RED);
      flame.setStrokeWidth(3);

      Group root = new Group(rocket, hatch, flame);

      Scene scene = new Scene(root, 400, 400, Color.BLACK);

      primaryStage.setTitle("Rocket");
      primaryStage.setScene(scene);
      primaryStage.show();
   }
}

 程序中的一些代码，并在我的 

QuitButtonExample.java

 程序中对其进行了一些修改，但它给了我一个错误，指出该程序可以简化。我不希望它被简化，我只是想找到一种方法来显示火箭图像和退出按钮，并在按下关闭程序时退出按钮起作用。我已经这样做有一段时间了，我通常不确定该怎么做。我想要一些提示来帮助我了解下一步该去哪里。下面我将发布我尝试过的代码。

Rocket1.java

Rocket.java

Answer 1

您的按钮处理程序可以工作；但您似乎将按钮添加到

import javafx.application.Application;
import javafx.application.Platform;
import javafx.event.ActionEvent;
import javafx.geometry.Insets;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Polygon;
import javafx.scene.shape.Polyline;
import javafx.stage.Stage;


public class Rocket extends Application
{
   //--------------------------------------------------------------------
   //  Displays a rocket lifting off. The rocket and hatch are polygons
   //  and the flame is a polyline.
   //--------------------------------------------------------------------
   public void start(Stage primaryStage)
   {
   double[] hullPoints = {200, 25, 240, 60, 240, 230, 270, 260, 
            270, 300, 140, 300, 140, 260, 160, 230, 160, 60};
      Polygon rocket = new Polygon(hullPoints);
      rocket.setFill(Color.BEIGE);
      double[] hatchPoints = {185, 70, 215, 70, 220, 120, 180, 120};

      Polygon hatch = new Polygon(hatchPoints);
      hatch.setFill(Color.MAROON);

      double[] flamePoints = {142, 310, 142, 330, 150, 325, 155, 380, 
               165, 340, 175, 360, 190, 350, 200, 375, 215, 330, 220, 360, 
               225, 355, 230, 370, 240, 340, 255, 370, 260, 335, 268, 340, 
               268, 310};

      Polyline flame = new Polyline(flamePoints);
      flame.setStroke(Color.RED);
      flame.setStrokeWidth(3);

      Group root = new Group(rocket, hatch, flame);
      
      Button btn = new Button();
        btn.setText("Quit");
        btn.setOnAction((ActionEvent event) -> {
            Platform.exit();
        });

        HBox exitButton = new HBox();
        exitButton.setPadding(new Insets(25));
        exitButton.getChildren().add(btn);
            
      Scene scene = new Scene(root, exitButton, 400, 400, Color.BLACK);

      primaryStage.setTitle("Rocket");
      primaryStage.setScene(scene);
      primaryStage.show(); 

   }
}

，而从未将 

Pane

 添加到传递给您的 

Pane

 的 

Parent

。下面的变体添加了按钮 

Scene

；然后它

然后将HBox

添加到名为

HBox

的

Group

中，然后它成为

场景图的根。

场景图，像

this一样遍历并为了清晰起见而省略：

root经测试：

Group@56d9b476[styleClass=root]
  Polygon[…]
  Polygon[[…]
  Polyline[…]
  HBox@25afbfbc
    Button@36457869[…]'Quit'
      Text[text="Quit", x=0.0, y=0.0, …]

Answer 2

看看我的这个辅助方法并用你的按钮执行它：

import javafx.application.Application;
import javafx.application.Platform;
import javafx.event.ActionEvent;
import javafx.geometry.Insets;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Polygon;
import javafx.scene.shape.Polyline;
import javafx.stage.Stage;

public class Rocket extends Application {
    //--------------------------------------------------------------------
    //  Displays a rocket lifting off. The rocket and hatch are polygons
    //  and the flame is a polyline.
    //--------------------------------------------------------------------

    @Override
    public void start(Stage primaryStage) {
        double[] hullPoints = {200, 25, 240, 60, 240, 230, 270, 260,
            270, 300, 140, 300, 140, 260, 160, 230, 160, 60};
        Polygon rocket = new Polygon(hullPoints);
        rocket.setFill(Color.BEIGE);
        double[] hatchPoints = {185, 70, 215, 70, 220, 120, 180, 120};

        Polygon hatch = new Polygon(hatchPoints);
        hatch.setFill(Color.MAROON);

        double[] flamePoints = {142, 310, 142, 330, 150, 325, 155, 380,
            165, 340, 175, 360, 190, 350, 200, 375, 215, 330, 220, 360,
            225, 355, 230, 370, 240, 340, 255, 370, 260, 335, 268, 340,
            268, 310};

        Polyline flame = new Polyline(flamePoints);
        flame.setStroke(Color.RED);
        flame.setStrokeWidth(3);

        Group root = new Group(rocket, hatch, flame);

        Button btn = new Button();
        btn.setText("Quit");
        btn.setOnAction((ActionEvent event) -> {
            Platform.exit();
        });

        HBox exitButton = new HBox(btn);
        exitButton.setPadding(new Insets(25));
        root.getChildren().add(exitButton);

        Scene scene = new Scene(root, 400, 400, Color.BLACK);

        primaryStage.setTitle("Rocket");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

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