按钮失去焦点时出现默认按钮

Question

按钮失去焦点： 按钮有焦点：

简短代码：

MLibrary = new JButton();
MenuPane.add(MLibrary, new AnchorConstraint(0, 0, 0, 0, AnchorConstraint.ANCHOR_ABS, AnchorConstraint.ANCHOR_NONE, AnchorConstraint.ANCHOR_ABS, AnchorConstraint.ANCHOR_ABS));
MLibrary.setText("Library");
setButtonDefaults(MLibrary);

MScheduler = new JButton();
MenuPane.add(MScheduler, new AnchorConstraint(0, 0, 0, 110, AnchorConstraint.ANCHOR_ABS, AnchorConstraint.ANCHOR_NONE, AnchorConstraint.ANCHOR_ABS, AnchorConstraint.ANCHOR_ABS));
MScheduler.setText("Scheduler");
setButtonDefaults(MScheduler);

private void setButtonDefaults(JButton but) { //calls in JPanel init only for setting button defaults
    but.setBorderPainted(false);
    but.setBackground(Color.DARK_GRAY);
    but.setForeground(Color.WHITE);
    but.setName(but.getText().toLowerCase());
    but.setPreferredSize(buttonSize);
    but.addActionListener(this);
}

private void enableOnlyOne(JButton but) {//calls each time when one of menu buttons are pressed. but is pressed button
    // TODO Auto-generated method stub
    setButtonDisabled(MLibrary);
    setButtonDisabled(MScheduler);
    setButtonDisabled(MBudget);
    setButtonDisabled(MReports);
    setButtonDisabled(MManage);
    setButtonDisabled(MSettings);
    //enable one
    //but.setFocusPainted(true);
    but.getModel().setPressed(true);
    but.setBackground(ContentPane.getBackground());
    but.setForeground(Color.BLACK);
}

private void setButtonDisabled(JButton but) { //sets button unpressed
    but.getModel().setPressed(false);
    but.setBackground(Color.DARK_GRAY);
    but.setForeground(Color.WHITE);
}

所以，我的问题是如何编码每个按钮，当按钮失去焦点时，它将是浅灰色背景，而不是默认外观

Answer 1

为每个按钮添加 Focus Listener 并实现功能public void focusLost(FocusEvent e)，并在功能内部设置按钮的背景。

来源： http://docs.oracle.com/javase/tutorial/uiswing/events/focuslistener.html

<强>更新

在focusLost(FocusEvent e)内，输入以下代码：

JButton button = (JButton) e.getSource();
e.setBackground(Color.Gray);