请帮初学者看下代码为什么不能运行

Question

package controler;
import newtest.*;

import java.awt.EventQueue;
import java.awt.event.ActionEvent;

import javax.swing.JFrame;

public class Controler extends JFrame{
	String op;double result;int a,b,c;
	AutoJudge auto=new AutoJudge();
	
			
	public void btnNew(ActionEvent e)//方法
	{
		a=(int)(Math.random()*9+1);
	    b=(int)(Math.random()*9+1);
		c=(int)(Math.random()*3+1);
		op="";result=0;
		switch(c)
		{
		case 0:
			op="+";result=a+b;
		case 1:	
			op="-";result=a-b;
		case 2:	
			op="*";result=a*b;
		case 3:
			op="/";result=a/b;
		}
		auto.jb1.setText(""+a);
		auto.jb2.setText(op);
		auto.jb3.setText(""+b);
		auto.textField.setText("");
		
	}
	public void btnJudge(ActionEvent e)
	{
		String str=auto.textField.getText();
		double d=Double.valueOf(str).doubleValue();
		String ans=""+a+op+b+"="+d+"";
		if(result==d)
			ans+="right!";
		else
			ans+="false!";
		auto.list.add(ans);
	}
}

以上是controler的代码段，用来实现逻辑。

然后是图形界面。

package newtest;
import controler.*;

import java.awt.BorderLayout;
import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JTextField;
import java.awt.Font;
import javax.swing.JList;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.*;
import java.awt.event.*;
import javax.swing.SwingConstants;

public class AutoJudge extends JFrame {
	Controler control=new Controler();
	private JPanel contentPane;
	public JTextField textField=new JTextField(); ;
	public JButton btnNew1 = new JButton("\u51FA\u9898");
	public JButton btnJudge1 = new JButton("\u5224\u5206");
	public JLabel jb1 = new JLabel("");//new为一个对象在堆中开辟了空间，这个空间里面有对象的方法和字段。
	public JLabel jb2 = new JLabel("");//在这里jb1与jb2等都不是对象本身，而是一个对象引用，或者说是对象指针。jb1与jb2存在于栈里面。而不是堆中。
	public JLabel jb3 = new JLabel("");//这里的等号意为把堆中的内存赋值给对象引用。
	public List list = new List(0);
	
	
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					AutoJudge frame = new AutoJudge();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}

	/**
	 * Create the frame.
	 */
	public AutoJudge() {
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 450, 300);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		
		btnNew1.setBounds(64, 69, 97, 23);
		contentPane.add(btnNew1);
		
		
		btnJudge1.setBounds(244, 69, 97, 23);
		contentPane.add(btnJudge1);
		
		JLabel jb4 = new JLabel("=");
		jb4.setHorizontalAlignment(SwingConstants.CENTER);
		jb4.setFont(new Font("宋体", Font.PLAIN, 37));
		jb4.setBounds(226, 8, 30, 42);
		contentPane.add(jb4);
		textField.setFont(new Font("宋体", Font.PLAIN, 28));
		
		
		textField.setBounds(266, 8, 97, 42);
		contentPane.add(textField);
		textField.setColumns(10);
		list.setFont(new Font("Dialog", Font.PLAIN, 18));
		
		
		list.setBounds(28, 108, 385, 153);
		contentPane.add(list);
		jb1.setFont(new Font("宋体", Font.PLAIN, 28));
		
		
		jb1.setBounds(87, 8, 43, 42);
		contentPane.add(jb1);
		jb2.setFont(new Font("宋体", Font.PLAIN, 28));
		
		
		jb2.setBounds(131, 8, 30, 42);
		contentPane.add(jb2);
		jb3.setFont(new Font("宋体", Font.PLAIN, 28));
		
		
		jb3.setBounds(173, 8, 43, 42);
		contentPane.add(jb3);
		 SymAction symAction=new SymAction();
		btnNew1.addActionListener( symAction );
		btnJudge1.addActionListener(symAction);
		
	}
	class SymAction implements java.awt.event.ActionListener
	{

		public void actionPerformed(ActionEvent e) {
			Object object=e.getSource();//获取事件源。
			if(object==btnNew1)
			{
				control.btnNew(e);
			}
			if(object==btnJudge1)	
			{
				 control.btnJudge(e);
			}
			
		}

		
	}
}

Answer 1

Controler类中用到AutoJudge类中的属性，全部设置为静态。Controller类中通过AutoJudge名直接调用静态成员变量。