import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Calculator01 extends JFrame implements ActionListener {
JPanel jp1,jp2;
JTextField jt1,jt2,jt3;
JButton btn_add,btn_sub,btn_clean;
public Calculator01() {
init();
}
public void init() {
setTitle("简易计算器");
setLocationRelativeTo(null);
setSize(600, 100);
jp1 = new JPanel();
jp2 = new JPanel();
add(jp1, BorderLayout.NORTH);
add(jp2,BorderLayout.SOUTH);
jt1 = new JTextField(15);
jp1.add(jt1);
jt2 = new JTextField(15);
jp1.add(jt2);
jt3 = new JTextField(15);
jp1.add(jt3);
btn_add = new JButton("+");
btn_add.addActionListener(this);
jp2.add(btn_add);
btn_sub = new JButton("-");
btn_sub.addActionListener(this);
jp2.add(btn_sub);
btn_clean = new JButton("清除");
btn_clean.addActionListener(this);
jp2.add(btn_clean);
setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
if (e.getSource() == btn_clean)
{
jt1.setText("");
jt2.setText("");
jt3.setText("");
}
else
{
if (jt1.getText().equals("") || jt2.getText().equals(""))
{
JOptionPane.showMessageDialog(null, "请在前两个框输入数字");
}
else
{
double number1=Double.parseDouble(jt1.getText());
double number2=Double.parseDouble(jt2.getText());
double result=0;
if (e.getSource() == btn_add)
{
result = number1 + number2;
}
else
{
result = number1 - number2;
}
jt3.setText(""+result);
}
}
}
}
这个没main方法吗
public class Test
{
public static void main(String[] args)
{
Calculator01 c = new Calculator01();
}
}