Question

我在Eclipse中创建了一个使用JavaFx和MVC模式的简单计算器。我想添加keylisteners，只需按下键盘上的按钮即可按下计算器的按钮。我试图在SceneBuilder中添加#onKeyPress，然后在我的Controller类中添加一个onKeypress方法（里面有一些编码），但没有任何反应。请你给出一些如何实现这样的通用指令？谢谢！

Answer 1

感谢您的评论。我在App.java中添加了以下代码片段：

scene.setOnKeyReleased(new EventHandler<KeyEvent>() {
   @Override
   public void handle(KeyEvent event) {         
    controller.numFromKeyboard(event.getCode().toString());
   }
});

而且，我必须补充：

Parent root = loader.load();
        Controller controller = loader.getController(); 
              // The above line MUST be
              // inserted after root is loaded in order the controller of my 
              // app to be instantiated, 
              // otherwise we will get a null exception when handler will be 
              // invoked

<强> App.java

public class App extends Application {

 //controller  = new Controller();

@Override
public void start(Stage primaryStage) {
    try {
        // Read file fxml and draw interface.
        FXMLLoader loader = new FXMLLoader(getClass()
                .getResource("/application/View.fxml"));


        Parent root = loader.load();
        Controller controller = loader.getController();
        Scene scene = new Scene(root);
        scene.getStylesheets().add(getClass().getResource("/application/application.css").toExternalForm());
        Image icon = new Image(getClass().getResourceAsStream("/application/Assets/App.png"));
        primaryStage.getIcons().add(icon);
        primaryStage.setTitle("JavaFX Calculator by Dimitris Baltas");
        primaryStage.setScene(scene);
        primaryStage.setResizable(false);         
        primaryStage.show();
        scene.setOnKeyReleased(new EventHandler<KeyEvent>() {
            @Override
            public void handle(KeyEvent event) {
               controller.numFromKeyboard(event.getCode().toString());
            }
        });
    } catch(Exception e) {
        e.printStackTrace();
    }
}

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

使用MVC在JavaFX中为计算器numpad添加KeyEvent

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