calculator.java

学习Java的一些基本课件和源代码 对于初学者很有帮助的

//Calculator.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Calculator extends JFrame
{
	private JPanel p1=new JPanel();
	private JButton numberButton[]=new JButton[10];
	private String buttonName[]={"1","2","3","4","5","6","7","8","9","0"};
	private JButton plusButton;
	private JButton calButton;
	private JLabel tf=new JLabel("计算：");
	private String add1="";
	private String add2="";
	private String output="";
	private int calResult;
	private boolean plusClicked=false;
    public Calculator(){
      super("简易加法器");
	  getContentPane().setLayout(null);
	  p1.setLayout(new GridLayout(3,4,15,10));
	  p1.setBounds(10,10,230,120);
	  for(int i=0;i<10;i++)
    	{	
    	  numberButton[i]=new JButton(buttonName[i]);
    	  numberButton[i].addActionListener(new Number());
    	  p1.add(numberButton[i]);
    	  }	
      plusButton=new JButton("+");
      plusButton.addActionListener(new Plus());
      p1.add(plusButton);
    
      calButton=new JButton("=");
      calButton.addActionListener(new Cal());
      p1.add(calButton);
      getContentPane().add(p1);
	
	  tf.setBounds(10,150,230,20);
	  getContentPane().add(tf);
	
	  setSize(280,200);
	  setVisible(true);
      setResizable(false);
    }
    class Number implements ActionListener
    {
	   public void actionPerformed(ActionEvent e)
	    {
	    	if(!plusClicked)
	    	{
			   add1+=e.getActionCommand();
			   output="计算："+add1;
			   tf.setText(output);
			}
	    	else
		    {
			   add2+=e.getActionCommand();
			   output+=e.getActionCommand();
			   tf.setText(output);
		    }
	     }
      }
     class Plus implements ActionListener
      {
        	public void actionPerformed(ActionEvent e)
         	{
		      plusClicked=!plusClicked;
		      output+=" + ";
		      tf.setText(output);
	         }
       }
     class Cal implements ActionListener
      {
 	     public void actionPerformed(ActionEvent e)
	     {
		     calResult=Integer.parseInt(add1)+Integer.parseInt(add2);
		     output+=" = ";
		     tf.setText(output+Integer.toString(calResult));
		     plusClicked=false;
		     add1="";
		     add2="";
	      }
       }
     public static void main(String args[])
      {	
  	     Calculator calculator=new Calculator();
	     calculator.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      }
}