Cannot listen to KeyEvent in JavaFX

2019-02-09 06:43发布

I want my JavaFX program to respond to keyboard events.
I tried adding listeners to root Pane, to topmost Pane, but it doesn't respond to events!
Here is my code:

   AnchorPane root = new AnchorPane();
   root.setOnKeyPressed(new EventHandler<KeyEvent>() {

        @Override
        public void handle(KeyEvent t) {
            pressKey(t.getCharacter().charAt(0));
        }
    });
    root.setOnKeyReleased(new EventHandler<KeyEvent>() {

        @Override
        public void handle(KeyEvent t) {
            releaseKey(t.getCharacter().charAt(0));
        }
    });
    root.addEventHandler(EventType.ROOT, new EventHandler<Event>() {

        @Override
        public void handle(Event t) {
            if (t.getClass().equals(KeyEvent.class)) {
                System.out.println("AAARGH! " + ((KeyEvent)t).getCharacter());
            }
        }
    });

WHY U NO WORKING, key events? Am I doing something wrong here?
To be sure, mouse events works fine with the same code.

3条回答
混吃等死
2楼-- · 2019-02-09 07:18

One solution is to add an event listener to the scene. Because layouts don't have focus by default, so they don't respond on KeyEvents. KeyEvents are passed to the focused node first.

Another solution is to make your pane focusable:

root.setFocusTraversable(true)
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爷的心禁止访问
3楼-- · 2019-02-09 07:20

also make sure you are importing the correct KeyEvent as in

import javafx.scene.input.KeyEvent;

rather than the KeyEvent from awt

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仙女界的扛把子
4楼-- · 2019-02-09 07:29

((KeyEvent)t).getCharacter() instead use ((KeyEvent)e).getText()

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