java - ActionEvent “Cannot Find Symbol”

Question

我正在制作一个程序，可以根据用户输入用文字或字符包装文本。我的所有工作正常，但ActionEvent却给我一个“找不到符号”错误。我敢肯定，我错过了一些小东西，但是我似乎找不到它:

import javax.swing.*;
import java.awt.*;
import javax.swing.border.*;

public class JTextWrap extends JFrame
{
   JScrollPane scroll = new JScrollPane();
   JPanel panel = new JPanel();
   JTextArea jta = new JTextArea();
   TitledBorder tb;
   JRadioButton jrb = new JRadioButton();
   JRadioButton jrb2 = new JRadioButton();
   ButtonGroup btg = new ButtonGroup();
   JCheckBox jdb = new JCheckBox();

   public JTextWrap()
   {
      tb = new TitledBorder("");
      setSize(new Dimension(400, 300));
      jta.setText("jTextArea1");
      panel.setBorder(tb);
      tb.setTitle("Wrap Options");
      jrb.setText("Wrap Words");
      jrb.addActionListener(
            new ActionListener()
            {
               public void actionPerformed(ActionEvent e) {
                  JTextWrap.jrb_actionPerformed(e);
               }
            });
      jrb2.setText("Wrap Characters");
      jrb2.addActionListener(
            new ActionListener()
            {
               public void actionPerformed(ActionEvent e) {
                  JTextWrap.jrb2_actionPerformed(e);
               }
            });
      jdb.setText("Wrap");
      jdb.addActionListener(
            new ActionListener()
            {
               public void actionPerformed(ActionEvent e) {
                  JTextWrap.jdb_actionPerformed(e);
               }
            });
      add(scroll, "Center");
      scroll.getViewport().add(jta, null);
      add(panel, "South");
      panel.add(jdb, null);
      panel.add(jrb, null);
      panel.add(jrb2, null);

      btg.add(jrb);
      btg.add(jrb2);
   }

   public static void main(String[] args)
   {
      JTextWrap frame = new JTextWrap();
      frame.setTitle("JTextWrap");
      frame.setDefaultCloseOperation(3);
      frame.setSize(400, 300);
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

   void jdb_actionPerformed(ActionEvent e) {
      jta.setLineWrap(jdb.isSelected());

      if (jdb.isSelected()) {
         jrb.setEnabled(true);
         jrb2.setEnabled(true);
      }
      else {
         jrb.setEnabled(false);
         jrb2.setEnabled(false);
      }
   }

   void jrb_actionPerformed(ActionEvent e) {
      jta.setWrapStyleWord(jrb.isSelected());
      jta.revalidate();
   }

   void jrb2_actionPerformed(ActionEvent e) {
      jta.setWrapStyleWord(!jrb2.isSelected());
      jta.revalidate();
   }
}

Answer 1

ActionEvent类在java.awt.event包中，您尚未导入此包。