package ex09_07;import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Frame1 extends JFrame {  JPanel contentPane;  JLabel jLabel1 = new JLabel();  ButtonGroup buttonGroup1 = new ButtonGroup();  JRadioButton jRadioButton1 = new JRadioButton();  JRadioButton jRadioButton2 = new JRadioButton();  JRadioButton jRadioButton3 = new JRadioButton();  /**Construct the frame*/  public Frame1() {    enableEvents(AWTEvent.WINDOW_EVENT_MASK);    try {      jbInit();    }    catch(Exception e) {      e.printStackTrace();    }  }  /**Component initialization*/  private void jbInit() throws Exception  {    //setIconImage(Toolkit.getDefaultToolkit().createImage(Frame1.class.getResource("[Your Icon]")));    contentPane = (JPanel) this.getContentPane();    jLabel1.setText("改變文字大小");    jLabel1.setBounds(new Rectangle(21, 17, 156, 27));    contentPane.setLayout(null);    this.setSize(new Dimension(400, 300));    this.setTitle("Frame Title");    jRadioButton1.setFont(new java.awt.Font("Dialog", 0, 14));    jRadioButton1.setText("18");    jRadioButton1.setBounds(new Rectangle(41, 48, 103, 27));    jRadioButton1.addActionListener(new java.awt.event.ActionListener() {      public void actionPerformed(ActionEvent e) {        jRadioButton1_actionPerformed(e);      }    });    jRadioButton2.setFont(new java.awt.Font("Dialog", 0, 14));    jRadioButton2.setText("16");    jRadioButton2.setBounds(new Rectangle(41, 77, 103, 27));    jRadioButton2.addActionListener(new java.awt.event.ActionListener() {      public void actionPerformed(ActionEvent e) {        jRadioButton2_actionPerformed(e);      }    });    jRadioButton3.setFont(new java.awt.Font("Dialog", 0, 14));    jRadioButton3.setText("12");    jRadioButton3.setBounds(new Rectangle(41, 105, 103, 27));    jRadioButton3.addActionListener(new java.awt.event.ActionListener() {      public void actionPerformed(ActionEvent e) {        jRadioButton3_actionPerformed(e);      }    });    contentPane.add(jLabel1, null);    contentPane.add(jRadioButton1, null);    contentPane.add(jRadioButton2, null);    contentPane.add(jRadioButton3, null);    buttonGroup1.add(jRadioButton1);    buttonGroup1.add(jRadioButton2);    buttonGroup1.add(jRadioButton3);  }  /**Overridden so we can exit when window is closed*/  protected void processWindowEvent(WindowEvent e) {    super.processWindowEvent(e);    if (e.getID() == WindowEvent.WINDOW_CLOSING) {      System.exit(0);    }  }  void jRadioButton1_actionPerformed(ActionEvent e) {//設置字體大小為18jLabel1.setFont(new Font("Dialog",0,18));  }  void jRadioButton2_actionPerformed(ActionEvent e) {//設置字體大小為16jLabel1.setFont(new Font("Dialog",0,16));  }  void jRadioButton3_actionPerformed(ActionEvent e) {//設置字體大小為12jLabel1.setFont(new Font("Dialog",0,12));  }}