代码如下，求大神解答，关于gui布局的，程序运行没出现任何东西？

Question

public class text_BJ extends Panel { private Panel panel1 = new Panel(); private Panel panel2 = new Panel(); public void text_BJ() {    Checkbox checkbox1, checkbox2;  CheckboxGroup a = new CheckboxGroup();  checkbox1 = new Checkbox("普通", true, a);  checkbox2 = new Checkbox("障碍", false, a);    TextField textField1;  textField1 = new TextField(10);    panel1.setLayout(new GridLayout(1, 2));  panel1.add(new Label("请输入用户名："));  panel1.add(textField1);  panel2.setLayout(new GridLayout(1, 3));  panel2.add(new Label("请选择游戏模式："));  panel2.add(checkbox1);  panel2.add(checkbox2);  setLayout(new GridBagLayout());  GridBagConstraints c = new GridBagConstraints();  c.gridx = 0;  c.gridy = 0;  add(panel1, c);  c.gridy = 1;  add(panel2, c); } public static void main(String[] args) throws InterruptedException {  Frame frame = new Frame("德玛西亚");  frame.add(new text_BJ());  frame.pack();  frame.setVisible(true);  frame.addWindowListener(new WindowAdapter() {   public void windowClosing(WindowEvent e) {    System.exit(0);   }  }); }}

Answer 1

你是不是没有把面板放在框架上？