java - 如何使用 Container 添加填充？

Question

我正在尝试在顶部做一些填充，但如何使用 Container 做到这一点？

    JFrame frame = super.screen.getFullScreenWindow();
    //Container contentPane = frame.getContentPane();
    //JPanel contentPane = new JPanel();

    // Make sure the content pane is transparent
    if (contentPane instanceof JComponent) {
        ((JComponent)contentPane).setOpaque(false);
    } 
    else {
      // ??
    }

    contentPane.setBorder(new EmptyBorder(10, 10, 10, 10) );
    //frame.getContentPane().add(contentPane, BorderLayout.CENTER);

输出

 [javac] symbol  : method setBorder(javax.swing.border.EmptyBorder)
 [javac] location: class java.awt.Container 
 [javac] contentPane.setBorder(new EmptyBorder(10, 10, 10, 10) );
 [javac]

Answer 1

您不能简单地添加一个 JPanel 来包含所有内容并在其上设置空边框吗？

 JPanel containerPanel = new JPanel();
 containerPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
 containerPanel.setLayout(new BorderLayout());
 //panel to test
 JPanel testPanel = new JPanel();
 testPanel.setBackground(Color.blue);        
 containerPanel.add(testPanel,BorderLayout.CENTER);

 //assuming you are extending JFrame
 getContentPane().setLayout(new BorderLayout());
 getContentPane().add(containerPanel, BorderLayout.CENTER);