cpanel1.java

用java实现计算器功能的程序

//********************************************************************
// CPanel1.java       Authors: vivi
//
//  big homework for q4
// make the panel and plus event listener
//********************************************************************

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

public class CPanel1 extends JPanel
{
  private JButton c,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,plus,minus,multiply,divide;
  private JLabel label;
  private String text="0"; 
  private int num=0,num1=0,num2=0,result=0;
  private char sign;
  private JPanel buttonPanel;
   	
  
   public CPanel1()
   {
   	  

       
   
     ButtonListener listener=new ButtonListener();

      JLabel label1 = new JLabel("");
      JLabel label2 = new JLabel("");
      JLabel label = new JLabel(text);
      JButton plus = new JButton("+");
      plus.addActionListener(listener);
      JButton minus = new JButton("-");
      minus.addActionListener(listener);
      JButton multiply = new JButton("*");
      multiply.addActionListener(listener);
      JButton divide = new JButton("/");
      JButton c = new JButton ("c");
      c.addActionListener(listener);
      JButton b1 = new JButton ("1");
      b1.addActionListener(listener);
      JButton b2 = new JButton ("2");
      b2.addActionListener(listener);
      JButton b3 = new JButton ("3");
      b3.addActionListener(listener);
      JButton b4 = new JButton ("4");
      b4.addActionListener(listener);
      JButton b5 = new JButton ("5");
      b5.addActionListener(listener);
      JButton b6 = new JButton ("6");
      b6.addActionListener(listener);
      JButton b7 = new JButton ("7");
      b7.addActionListener(listener);
      JButton b8 = new JButton ("8");
      b8.addActionListener(listener);
      JButton b9 = new JButton ("9");
      b9.addActionListener(listener);
      JButton b10 = new JButton ("0");
      b10.addActionListener(listener);
      JButton b11 = new JButton ("+/-");
      b11.addActionListener(listener);
      JButton b12 = new JButton ("=");
      b12.addActionListener(listener);
         
      buttonPanel = new JPanel();
      setLayout (new GridLayout (5, 4));
      buttonPanel.setPreferredSize(new Dimension(100,270));
      buttonPanel.setBackground(Color.blue);

     
      buttonPanel.add (c);
      buttonPanel.add (b1);
      buttonPanel.add (b2);
      buttonPanel.add (b3);
      buttonPanel.add (plus);
      buttonPanel.add (b4);
      buttonPanel.add (b5);
      buttonPanel.add (b6);
      buttonPanel.add (minus);
      buttonPanel.add (b7);
      buttonPanel.add (b8);
      buttonPanel.add (b9);
      buttonPanel.add (multiply);
      buttonPanel.add (b10);
      buttonPanel.add (b11);
      buttonPanel.add (b12);
      buttonPanel.add (divide);
      
       setBackground (Color.white);
       setPreferredSize(new Dimension(300,270) );
       
       add (label1);
      add (label2);
      add (label);
      add(buttonPanel);
      
     
   }

private class ButtonListener implements ActionListener
   {
     public void actionPerformed(ActionEvent event)
     {
     if(event.getSource()== b1) 
   	    	  	num=num*10+1;
   	    	  	
   	    	if(event.getSource()== b2) 
   	    	   	num=num*10+2;
   	    	  	
   	    	if(event.getSource()== b3)
   	    	    num=num*10+3;
   	    
   	    	if(event.getSource()== b4) 
   	      	  	num=num*10+4;
   	    	
   	    	if(event.getSource()== b5) 
   	    	 	  	num=num*10+5;
   	    	  	
   	    	if(event.getSource()== b6) 
   	      	  	num=num*10+6;
   	    
   	    	if(event.getSource()== b7) 
   	    	 	  	num=num*10+7;
   	    	 
   	    	if(event.getSource()== b8)
   	      	  	num=num*10+8;
   	    	  	
   	    	if(event.getSource()== b9) 
   	    	 	  	num=num*10+9;
   	    	
   	    	if(event.getSource()== b10) 
   	    	 	  	num=num*10;
   	    	  
   	    	if(event.getSource()== b11) 
   	    	   num=num*-1;
   	    
   	  result=num;
     label.setText(Integer.toString(result));
    //repaint();
     }
   }  
 }