各位慕友啊，为什么我的40~42行显示找不到符号的错误呢？

Question

import java.awt.*;import java.awt.event.*;import javax.swing.*;import javax.swing.event.*;import java.lang.String;public class Calculate{public static void main (String[] args){FrameSize frame = new FrameSize();frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.show();}}class FrameSize extends JFrame{public FrameSize(){  setSize(600,400); //设置框架尺寸  ButtonPanel panel2 = new ButtonPanel();  Container contentPane = getContentPane();contentPane.add(panel2);  }}//创建按钮面板class ButtonPanel extends JPanel {public ButtonPanel(){JButton Button1 = new JButton("0"); //创建按钮JButton Button2 = new JButton("1");JButton Button3 = new JButton("2");add(Button1);  add(Button2);add(Button3);ButtonAction ButtonAction1 = new ButtonAction("1"); //40行找不到符号ButtonAction ButtonAction2 = new ButtonAction("2"); //41行找不到符号ButtonAction ButtonAction3 = new ButtonAction("3"); //42行找不到符号Button1.addActionListener(ButtonAction1);  Button2.addActionListener(ButtonAction2);Button3.addActionListener(ButtonAction3);}private class ButtonAction implements ActionListener{public void actionPerformed(ActionEvent event){Object source = event.getSource();if(source == Button1) ButtonText = "0";else if(source == Button2) ButtonText = "1";else if(source == Button3) ButtonText = "2";  repaint();}}private JButton Button1;private JButton Button2;private JButton Button3;public String ButtonText=" ";}

Answer 1

你这BUTTONACTION什么意思啊!?有这么一个语句的吗?

private class ButtonAction implements ActionListener
这个里面,你自己都写了点3个BUTTON的不同情况时候设计BUTTONTEXT的情况了.为什么还要搞3个BUTTONACTION?

试一下把下面3行删除
ButtonAction ButtonAction1 = new ButtonAction("1"); //40行找不到符号
ButtonAction ButtonAction2 = new ButtonAction("2"); //41行找不到符号
ButtonAction ButtonAction3 = new ButtonAction("3"); //42行找不到符号

下面的是改的:
Button1.addActionListener(new ButtonAction() );  
Button2.addActionListener(new ButtonAction());
Button3.addActionListener(new ButtonAction());

这样应该能达到你的效果.

Answer 2

你并没有定义ButtonAction类的构造函数
但在声名对象时却传入了参数，当然不行啊！
例如ButtonAction ButtonAction1 = new ButtonAction("1");中的参数"1"，给删了，能运行
你这个程序是测试程序吗？运行没有实际的效果出现。