如何在java中聚焦时获取实际的文本字段

Question

当我点击他并在其他地方点击时更改颜色时，如何将颜色设置为文本字段？ 我有2维文本字段数组。 当我使用这个代码时，它在最后一个texfield上设置颜色：/我如何获得聚焦的文本字段？ 谢谢

        window.getContentPane().setLayout(new GridLayout(1,2));
    Border lineBorder = new LineBorder(Color.BLACK,2);

    JPanel p2 = null;
    JPanel p1 =  new JPanel(new GridLayout(3,3));
    for (int k =0; k<9; k++)
    {
        p2 = new JPanel(new GridLayout(3,3));

        p2.setBorder(lineBorder);
        for(int i =0; i <=8; i++){
            a = k;
            b = i;
            p2.add(tf[k][i] = new JTextField(1), BorderLayout.CENTER);
            tf[k][i].setHorizontalAlignment(JTextField.CENTER);

            tf[k][i].addMouseListener(new MouseAdapter(){
                public void mouseClicked(MouseEvent e){
                    tf[a][b].setBackground(Color.BLACK);
                }
            });
        }
        for(int i = 0; i <=8; i++){
            p1.add(p2);
        }
    }

    JPanel p3 = new JPanel();

Answer 1

您可以像这样使用addFocusListener

JTextField myTextField = new JTextField();
myTextField.addFocusListener(new FocusListener() {
    @Override
    public void focusGained(FocusEvent fe) {
        myTextField.setForeground(Color.RED);
    }

    @Override
    public void focusLost(FocusEvent fe) {
        myTextField.setForeground(Color.GREEN);
    }
});