Java实现计算器
时间:2011-01-19
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import java.applet.Applet;
import javax.swing.*;
import javax.swing.border.*;
public class Calculator extends JApplet implements ActionListener
{
private final String[] KEYS={"7","8","9","/","sqrt",
"4","5","6","*","%",
"1","2","3","-","1/x",
"0","+/-",".","+","="
};
private final String[] COMMAND={"Backspace","CE","C"};
private final String[] M={" ","MC","MR","MS","M+"};
private JButton keys[]=new JButton[KEYS.length];
private JButton commands[]=new JButton[COMMAND.length];
private JButton m[]=new JButton[M.length];
private JTextField display =new JTextField("0");
// public JTextField setHorizontalAlignment(int alignment);
// private JTextField display.setHorizontalAlignment(JTextField.RIGHT)=new JTextField("0");
private void setup()
{
display.setHorizontalAlignment(JTextField.RIGHT);
JPanel calckeys=new JPanel();
JPanel command=new JPanel();
JPanel calms=new JPanel();
calckeys.setLayout(new GridLayout(4,5,3,3));
command.setLayout(new GridLayout(1,3,3,3));
calms.setLayout(new GridLayout(5,1,3,3));
for(int i=0;i<KEYS.length;i++)
{
keys[i]=new JButton(KEYS[i]);
calckeys.add(keys[i]);
keys[i].setForeground(Color.blue);
}
keys[3].setForeground(Color.red);
keys[4].setForeground(Color.red);
keys[8].setForeground(Color.red);
keys[9].setForeground(Color.red);
keys[13].setForeground(Color.red);
keys[14].setForeground(Color.red);
keys[18].setForeground(Color.red);
keys[19].setForeground(Color.red);
for(int i=0;i<COMMAND.length;i++)
{
commands[i]=new JButton(COMMAND[i]);
command.add(commands[i]);
commands[i].setForeground(Color.red);
}
for(int i=0;i<M.length;i++)
{
m[i]=new JButton(M[i]);
calms.add(m[i]);
m[i].setForeground(Color.red);
}
JPanel panel1=new JPanel();
panel1.setLayout(new BorderLayout(3,3));
panel1.add("North",command);
panel1.add("Center",calckeys);
JPanel top=new JPanel();
top.setLayout(new BorderLayout());
display.setBackground(Color.WHITE);
top.add("Center",display);
getContentPane().setLayout(new BorderLayout(3,5));
getContentPane().add("North",top);
getContentPane().add("Center",panel1);
getContentPane().add("West",calms);
}
public void init()
{
setup();
for(int i=0;i<KEYS.length;i++)
{
keys[i].addActionListener(this);
}
for(int i=0;i<COMMAND.length;i++)
{
commands[i].addActionListener(this);
}
for(int i=0;i<M.length;i++)
{
m[i].addActionListener(this);
}
display.setEditable(false);
}
public void actionPerformed(ActionEvent e)
{
String label=e.getActionCommand();
// double zero=e.getActionCommand();
if(label=="C")
handleC();
e
|
