Java JPanel 两个边框，不同的颜色？

Question

对于我的布局，我想要双边框，在我的 JPanel 底部，一个应该稍暗，另一个应该稍微亮一些。

目前我有 1 个边框:

JPanel pnlTop = new JPanel(new BorderLayout()) {
    protected void paintComponent(Graphics grphcs) {
        super.paintComponent(grphcs);
        Graphics2D g2d = (Graphics2D) grphcs;
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        GradientPaint gp = new GradientPaint(0, 0,
                new java.awt.Color(237, 237, 237), 0, getHeight(),
                new java.awt.Color(222, 222, 222));
        g2d.setPaint(gp);
        g2d.fillRect(0, 0, getWidth(), getHeight()); 
    }
};
pnlTop.setBorder(BorderFactory.createMatteBorder(0, 0, 1, 0, new java.awt.Color(173, 173, 166)));
pnlTop.setPreferredSize(new Dimension(2000, 90));
add(pnlTop, BorderLayout.PAGE_START);

如何在已有的边框下方添加另一个边框？这可能吗？

Answer 1

使用CompoundBorder

即...

pnlTop.setBorder(new CompoundBorder(
    BorderFactory.createMatteBorder(0, 0, 1, 0, Color.BLUE), 
    BorderFactory.createMatteBorder(0, 0, 1, 0, Color.RED));

参见 How to use Borders了解更多详情