java GUI 计算器代码

Question

package cn.itcast.chapter11;
import java.awt.*;
//import java.awt.event.*;
import javax.swing.*;
public class Text{
public Text() {
StringBuffer str;//要显示的字符串
JFrame jf=new JFrame("计算器");//创建一个窗口
jf.setSize(600,500);
jf.setLocation(600,300);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.setLayout(new BorderLayout());
JPanel jpanel1=new JPanel();//为按钮创建panel组件
JPanel jpanel2=new JPanel();//为文本框和CE键创建panel组件
JTextField jtf=new JTextField(45);//创建文本框
jtf.setEditable(false);//设置文本不可编辑
jpanel1.setLayout(new GridLayout(4,4));

JButton but1=new JButton("1");//创建按钮
JButton but2=new JButton("2");
JButton but3=new JButton("3");
JButton but10=new JButton("+");
JButton but4=new JButton("4");
JButton but5=new JButton("5");
JButton but6=new JButton("6");
JButton but11=new JButton("-");
JButton but7=new JButton("7");
JButton but8=new JButton("8");
JButton but9=new JButton("9");
JButton but12=new JButton("*");
JButton but16=new JButton(".");
JButton but0=new JButton("0");

JButton but14=new JButton("=");
JButton but13=new JButton("/");
JButton but15=new JButton("CE");

jpanel1.add(but1);//添加按钮
jpanel1.add(but2);
jpanel1.add(but3);
jpanel1.add(but10);
jpanel1.add(but4);
jpanel1.add(but5);
jpanel1.add(but6);
jpanel1.add(but11);
jpanel1.add(but7);
jpanel1.add(but8);
jpanel1.add(but9);
jpanel1.add(but12);
jpanel1.add(but16);
jpanel1.add(but0);

jpanel1.add(but14);
jpanel1.add(but13);
jpanel2.add(jtf);
jpanel2.add(but15);
jf.add(jpanel2,BorderLayout.NORTH);
jf.add(jpanel1,BorderLayout.CENTER);
jf.setVisible(true);
MyActionListener ac1=new MyActionListener();
but1.addActionListener(ac1);//添加动作监听器
}
class MyActionListener implements ActionListener{
public void actionPerformed(ActionEvent e) {
jtf.setText(e.getActionCommand());
}
}
public static void main(String[] args) {
new Text();
}
}
后面动作监听器那里错了，为什么，成员内部类不能继承java自己定义的类吗？

Answer 1

可以了，你之前的jtf变量，你自定义的监听器肯定访问不了，可以运行了，另外，下回发，记得格式化一下代码.

 import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//import java.awt.event.*;
import javax.swing.*;

public class Main {
    private JTextField jtf = null;

    public Main() {
        StringBuffer str;//要显示的字符串
        JFrame jf = new JFrame("计算器");//创建一个窗口
        jf.setSize(600, 500);
        jf.setLocation(600, 300);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setLayout(new BorderLayout());
        JPanel jpanel1 = new JPanel();//为按钮创建panel组件
        JPanel jpanel2 = new JPanel();//为文本框和CE键创建panel组件
        jtf = new JTextField(45);//创建文本框
        jtf.setEditable(false);//设置文本不可编辑
        jpanel1.setLayout(new GridLayout(4, 4));

        JButton but1 = new JButton("1");//创建按钮
        JButton but2 = new JButton("2");
        JButton but3 = new JButton("3");
        JButton but10 = new JButton("+");
        JButton but4 = new JButton("4");
        JButton but5 = new JButton("5");
        JButton but6 = new JButton("6");
        JButton but11 = new JButton("-");
        JButton but7 = new JButton("7");
        JButton but8 = new JButton("8");
        JButton but9 = new JButton("9");
        JButton but12 = new JButton("*");
        JButton but16 = new JButton(".");
        JButton but0 = new JButton("0");

        JButton but14 = new JButton("=");
        JButton but13 = new JButton("/");
        JButton but15 = new JButton("CE");

        jpanel1.add(but1);//添加按钮
        jpanel1.add(but2);
        jpanel1.add(but3);
        jpanel1.add(but10);
        jpanel1.add(but4);
        jpanel1.add(but5);
        jpanel1.add(but6);
        jpanel1.add(but11);
        jpanel1.add(but7);
        jpanel1.add(but8);
        jpanel1.add(but9);
        jpanel1.add(but12);
        jpanel1.add(but16);
        jpanel1.add(but0);

        jpanel1.add(but14);
        jpanel1.add(but13);
        jpanel2.add(jtf);
        jpanel2.add(but15);
        jf.add(jpanel2, BorderLayout.NORTH);
        jf.add(jpanel1, BorderLayout.CENTER);
        jf.setVisible(true);
        MyActionListener ac1 = new MyActionListener();
        but1.addActionListener(ac1);//添加动作监听器
    }

    class MyActionListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            jtf.setText(e.getActionCommand());
        }
    }

    public static void main(String[] args) {
        new Main();
    }
}