java-如何在单击时动态地将swing组件添加到gui？

动态添加按钮的示例代码。

panel.add(new JButton("Button"));validate();

完整代码：

import javax.swing.Jframe;import javax.swing.JButton;import javax.swing.JPanel;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.FlowLayout;import java.awt.BorderLayout;public class AddComponentOnJframeAtRuntime extends Jframe implements ActionListener {    JPanel panel;    public AddComponentOnJframeAtRuntime() {        super("Add component on Jframe at runtime");        setLayout(new BorderLayout());        this.panel = new JPanel();        this.panel.setLayout(new FlowLayout());        add(panel, BorderLayout.CENTER);        JButton button = new JButton("CLICK HERE");        add(button, BorderLayout.SOUTH);        button.addActionListener(this);        setDefaultCloseOperation(Jframe.EXIT_ON_CLOSE);        setSize(500, 500);        setVisible(true);    }    public void actionPerformed(ActionEvent evt) {        this.panel.add(new JButton("Button"));        this.panel.revalidate();        validate();    }    public static void main(String[] args) {        AddComponentOnJframeAtRuntime acojfar = new AddComponentOnJframeAtRuntime();    }}