一个非常非常简单的计算器

       今天被要求写个iphone上的计算器，毕竟还不是很熟，就先花一个小时用Java写了个，过下流程，非常非常简单。代码如下：

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package calculator;

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 *
 * @author GL
 */
public class Calculator extends JFrame{

    /**
     * @param args the command line arguments
     */
    
    int first = 0;
    int second = 0;
    int select = 0;
    int counter = 0;
    input in;
    JLabel out = new JLabel("0");
    
    public static void main(String[] args) {
        // TODO code application logic here
        JFrame j = new Calculator();
    }
    
    public Calculator(){
        in = new input();
        setLayout(new BorderLayout());
        add(in,BorderLayout.CENTER);
        add(out,BorderLayout.NORTH);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setTitle("Calculator");
       
    }
    
    class input extends JPanel{
        public input(){
            setLayout(new GridLayout(5,4));
            JButton[] enter = new JButton[20];
            
            enter[0] = new JButton("c");
            enter[1] = new JButton("<-");
            enter[2] = new JButton("/");
            enter[3] = new JButton("*");
            enter[4] = new JButton("7");
            enter[5] = new JButton("8");
            enter[6] = new JButton("9");
            enter[7] = new JButton("-");
            enter[8] = new JButton("4");
            enter[9] = new JButton("5");
            enter[10] = new JButton("6");
            enter[11] = new JButton("+");
            enter[12] = new JButton("1");
            enter[13] = new JButton("2");
            enter[14] = new JButton("3");
            enter[15] = new JButton("=");
            enter[16] = new JButton("0");
            enter[17] = new JButton(".");
            enter[18] = new JButton("+/-");
            enter[19] = new JButton("f");
            
            enter[0].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                    first = 0;
                    second = 0;
                    select = 0;
                    out.setText("0");
                }
            });
            
            enter[1].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    throw new UnsupportedOperationException("Not supported yet.");
                }
            });
            
             enter[2].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                    select = 4;
                    counter = 0;
                    out.setText("/");
                }
            });
            
              enter[3].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   select = 3;
                   counter = 0;
                   out.setText("*");
                }
            });
            
               enter[4].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   if(select == 0){
                       first = 7 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 7 + (int)(second*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                enter[5].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                     if(select == 0){
                       first = 8 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 8 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                 enter[6].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                     if(select == 0){
                       first = 9 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 9 + (int)(second*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                  enter[7].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   select = 2;
                   counter = 0;
                   out.setText("-");
                }
            });
            
                   enter[8].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                     if(select == 0){
                       first = 4 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 4 + (int)(second*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                    enter[9].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                     if(select == 0){
                       first = 5 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 5 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                     enter[10].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                     if(select == 0){
                       first = 6 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 6 + (int)(second*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                      enter[11].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   select = 1;
                   counter = 0;
                   out.setText("+");
                }
            });
            
                       enter[12].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                     if(select == 0){
                       first = 1 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 1 + (int)(second*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                        enter[13].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   if(select == 0){
                       first = 2 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 2 + (int)(second*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                         enter[14].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   if(select == 0){
                       first = 3 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 3 + (int)(second*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                          enter[15].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   switch(select){
                       case 1:
                           out.setText(String.valueOf(first+second));
                           break;
                       case 2:
                            out.setText(String.valueOf(first-second));
                           break;
                       case 3:
                            out.setText(String.valueOf(first*second));
                           break;
                       case 4:
                            out.setText(String.valueOf(first/second));
                           break;
                   }
                   
                   first = 0;
                   second = 0;
                   select = 0;
                   counter = 0;
                }
            });
            
                           enter[16].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   if(select == 0){
                       first = 0 + (int)(first*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(first));        
                   }
                   else{
                       second = 0 + (int)(second*Math.pow(10, counter));
                       counter++;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                            enter[17].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   
                }
            });
            
                             enter[18].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   if(select == 0){
                   
                       first = 0 -first;
                       out.setText(String.valueOf(first));
                   }
                   
                   else {
                       second = 0- second;
                       out.setText(String.valueOf(second));
                   }
                }
            });
            
                              enter[19].addActionListener(new ActionListener( ) {
                @Override
                public void actionPerformed(ActionEvent e) {
                    //throw new UnsupportedOperationException("Not supported yet.");
                   
                }
            });
                              
            for(int i = 0; i < 20; i++){
                add(enter[i]);
            }
            
        }
    }
}

最后运行的结果是：

界面很丑吧，我也觉的很丑，无所谓啦。稍微测试了下，应该没什么问题。