Java - 密钥绑定不起作用

Question

I try this simple code and System.out.println works when zoom button not pressed. But after pressing zoom button System.out.println not works. Why?

    zoomFree.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent ae) {
            isZoomFree = true;
            chartPanel.setDomainZoomable(true);
            chartPanel.setRangeZoomable(true);
            zoomIn.setEnabled(false);
            zoomFree.setEnabled(false);
        }
    });

    Action escapeZoom = new AbstractAction() {
        @Override
        public void actionPerformed(ActionEvent e) {
            System.out.println("ESCAPE pressed! yahoo!");
        }
    };

    panel.getInputMap().put(KeyStroke.getKeyStroke("ESCAPE"), "escape pressed");
    panel.getActionMap().put("escape pressed", escapeZoom);

Answer 1

When you pass no arguments to the getInputMap method, your key bindings will work only if the component is focused.

Try using getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW) instead:

panel.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("ESCAPE"), "escape pressed");
panel.getActionMap().put("escape pressed", escapeZoom);

This way the component doesn't need to have the focus, they will work when the window has the focus