counter3.java

用JAVA编写的一个小的计算器

/**
 * @(#)Counter2.java
 *
 *
 * @author 
 * @version 1.00 2008/11/3
 */


import java.awt.*; 
import javax.swing.*; 
import java.awt.event.*; 
class Counter2 extends WindowAdapter 
{ 
static JFrame f=new JFrame("计算器"); 
static JTextField text1=new JTextField("0."); 
static String source=""; 
static String cal=""; 
static String object=""; 
static boolean flag=false; 
static boolean flag1=true; 
static boolean flag2=false; 
public void init() 
{ 
try 
{ 
Container c=f.getContentPane(); 
JPanel pan1=new JPanel(); 
JButton b1=new JButton("1"); 
JButton b2=new JButton("2"); 
JButton b3=new JButton("3"); 
JButton b4=new JButton("4"); 
JButton b5=new JButton("5"); 
JButton b6=new JButton("6"); 
JButton b7=new JButton("7"); 
JButton b8=new JButton("8"); 
JButton b9=new JButton("9"); 
JButton b0=new JButton("0"); 
JButton b11=new JButton("+"); 
JButton b12=new JButton("-"); 
JButton b13=new JButton("*"); 
JButton b14=new JButton("/"); 
JButton b15=new JButton("."); 
JButton b16=new JButton("="); 
JButton bclar=new JButton("清0"); 
text1.setHorizontalAlignment(JTextField.RIGHT); 
c.add(text1,"North"); 
c.add(pan1); 
A aa=new A(); 
Result re=new Result(); 
Opertion op=new Opertion(); 
Clar cl=new Clar(); 
b1.addActionListener(aa); 
b2.addActionListener(aa); 
b3.addActionListener(aa); 
b4.addActionListener(aa); 
b5.addActionListener(aa); 
b6.addActionListener(aa); 
b7.addActionListener(aa); 
b8.addActionListener(aa); 
b9.addActionListener(aa); 
b0.addActionListener(aa); 
b11.addActionListener(op); 
b12.addActionListener(op); 
b13.addActionListener(op); 
b14.addActionListener(op); 
b16.addActionListener(re); 
b15.addActionListener(aa); 
bclar.addActionListener(cl); 
pan1.add(b1); 
pan1.add(b2); 
pan1.add(b3); 
pan1.add(b11); 
pan1.add(b4); 
pan1.add(b5); 
pan1.add(b6); 
pan1.add(b12); 
pan1.add(b7); 
pan1.add(b8); 
pan1.add(b9); 
pan1.add(b13); 
pan1.add(b0); 
pan1.add(b15); 
pan1.add(b16); 
pan1.add(b14); 
pan1.add(bclar); 
f.setSize(200,220); 
f.setVisible(true); 
} 
catch(Exception e) 
{ 
System.out.println(e.getMessage()); 
} 

} 
class A implements ActionListener 
{ 
public void actionPerformed(ActionEvent e) 
{ 
String a=text1.getText(); 
String s=e.getActionCommand(); 
if(a.equals("0.")||a.equals("+")||a.equals("-")||a.equals("*")||a.equals("/")) 
text1.setText(s); 
else { 
if(flag2) 
{ 
text1.setText(s); 
flag2=false; 
} 
else 
text1.setText(a+s); 

} 
} 
} 
class Opertion implements ActionListener 
{ 
public void actionPerformed(ActionEvent e) 
{ 
cal=e.getActionCommand(); 
if(flag1==true) 
source=text1.getText(); 
text1.setText(cal); 
flag1=false; 
flag=true; 
} 
} 
class Result implements ActionListener 
{ 
public void actionPerformed(ActionEvent e) 
{ 
double num1; 
num1=Double.parseDouble(source); 
object=text1.getText(); 
double num2; 
num2=Double.parseDouble(object); 
double result=0; 
if(cal.equals("+")) 
result=num1+num2; 
if(cal.equals("-")) 
result=num1-num2; 
if(cal.equals("*")) 
result=num1*num2; 
if(cal.equals("/")) 
if(num2==0) 
text1.setText("3yêy2??ü?a0"); 
else 
result=num1/num2; 
String s1=Double.toString(result); 
text1.setText(s1); 
flag1=true; 
flag2=true; 
} 
} 
class Clar implements ActionListener 
{ 
public void actionPerformed(ActionEvent e) 
{ 
text1.setText("0."); 
} 
} 

public static void main(String[] args) 
{ 
Counter2 count=new Counter2(); 
count.init(); 
} 

public void windowClosing(WindowEvent e){ 
System.exit(1); 
} 
public void windowOpened(WindowEvent e){} 
public void windowIconified(WindowEvent e){} 
public void windowDeiconified(WindowEvent e){} 
public void windowClosed(WindowEvent e){} 
public void windowActivated(WindowEvent e){} 
public void windowDeactivated(WindowEvent e){} 
}