KeyEvent停止听JavaFX

Question

我有一个非常简单的KeyEvent：

@Override
public void start(Stage stage) throws Exception {
    Group root = new Group();
    Scene scene = new Scene(root);
    Canvas canvas = new Canvas( 900, 700 );

    scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
        @Override
        public void handle(KeyEvent ke) {

            switch (ke.getCode()) {
                case UP:
                    System.out.println("UP");
                    break;
                case DOWN:
                    System.out.println("DOWN");
                    break;
                case LEFT:
                    System.out.println("LEFT");
                    break;
                case RIGHT:
                    System.out.println("RIGHT");
                    break;
                case ENTER:
                    //ke.consume();
                    break;
                default:
                    break;
            }
        }});

我喜欢达到的目标:我开始运行程序，如果我按上、下、左、右，输出写回给我，向上，向下，左，右(这是正确的，没有问题)。但!如果我按回车，如果我要按上、下、左、右、输入或其他键，不要将输出写回上、下、左、右。

所以当我按下ENTER按钮时，我就会停止KeyEvent的“运行”。

Answer 1

你有几个机会，这两个我先想到的。

1)将键事件的侦听器存储为类的成员，并在输入时按下取消注册.

private EventHandler<KeyEvent> keyHandler;


@Override
public void start(Stage stage) {
    final Scene scene = new Scene(new Group());
    stage.setTitle("Table View Sample");
    stage.setWidth(450);
    stage.setHeight(500);

    keyHandler = new EventHandler<KeyEvent>() {
        @Override
        public void handle(KeyEvent ke) {

            switch (ke.getCode()) {
                case ENTER:
                    scene.removeEventHandler(KeyEvent.KEY_PRESSED, keyHandler);
                    break;
                case UP:
                    System.out.println("UP");
                    break;
                case DOWN:
                    System.out.println("DOWN");
                    break;
                case LEFT:
                    System.out.println("LEFT");
                    break;
                case RIGHT:
                    System.out.println("RIGHT");
                    break;


                default:
                    break;
            }
        }};

   scane.addEventHandler(KeyEvent.KEY_PRESSED, keyHandler);

( 2)在按下输入键时，将布尔值存储到成员，如果设置了该成员，则使用事件.。

private Boolean enterPressed = false;

@Override
public void start(Stage stage) {
    final Scene scene = new Scene(new Group());
    stage.setTitle("Table View Sample");
    stage.setWidth(450);
    stage.setHeight(500);

   scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
        @Override
        public void handle(KeyEvent ke) {

            if(enterPressed){
                ke.consume();
                return;
            }

            switch (ke.getCode()) {
                case ENTER:
                    enterPressed = true;
                    break;
                case UP:
                    System.out.println("UP");
                    break;
                case DOWN:
                    System.out.println("DOWN");
                    break;
                case LEFT:
                    System.out.println("LEFT");
                    break;
                case RIGHT:
                    System.out.println("RIGHT");
                    break;

                default:
                    break;
            }
        }});

两者都在工作，选择你喜欢的任何东西。