import javax.swing.*;
import java.awt.*;
//導入ActionEvent事件包
import java.awt.event.*;
public class DynamicButtonDemo extends JFrame
    //實現ActionListener接口
    implements ActionListener {
  private  JButton btn;
  boolean state=true; //控制按鈕變化的變量
  public DynamicButtonDemo()   {
    super("動態按鈕");
    setSize(260,200);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    btn=new JButton("動態按鈕");
    //將框架對象注冊為事件監聽器
    btn.addActionListener(this);
    getContentPane().add(btn);
  }
  public static void main(String[] args)   {
    DynamicButtonDemo frame = new DynamicButtonDemo();
    frame.show();
  }
  //實現ActionEvent事件處理方法
  public void actionPerformed(ActionEvent e) {
    //判斷事件源
    if(e.getSource() instanceof JButton){
      //根據變量state設置不同按鈕標題
      if(state){
         btn.setText("點擊按鈕");
      }else
      {
        btn.setText("動態按鈕");
      }
     state=!state;
    }
  }
}