天若有情天亦老,人学物理数学金融生物死得早

* 计算器程序
***************************************/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Calculationer extends JFrame implements ActionListener {
// 窗口组件
private JPanel panel = new JPanel();
private JTextField text = new JTextField();
private JButton[] number = new JButton[10];
private JButton bt1, bt2, bt3, bt4, bt5, bt6, bt7, bt8;
String string = "";

// "画"窗口
public Calculationer() {
setTitle("Calculationer");
setResizable(false);
for (int i = 0; i < 10; i++) {
number[i] = new JButton("" + i);
number[i].addActionListener(this);
}
text.setEditable(false);
bt1 = new JButton(".");
bt1.addActionListener(this);
bt2 = new JButton("=");
bt2.addActionListener(this);
bt3 = new JButton("+");
bt3.addActionListener(this);
bt4 = new JButton("-");
bt4.addActionListener(this);
bt5 = new JButton("*");
bt5.addActionListener(this);
bt6 = new JButton("/");
bt6.addActionListener(this);
bt7 = new JButton("√");
bt7.addActionListener(this);
bt8 = new JButton("C");
bt8.addActionListener(this);
panel.setLayout(new GridLayout(6, 3, 7, 7));
for (int i = 7; i <= 9; i++)
panel.add(number[i]);
for (int i = 4; i <= 6; i++)
panel.add(number[i]);
for (int i = 1; i <= 3; i++)
panel.add(number[i]);
panel.add(number[0]);
panel.add(bt1);
panel.add(bt7);
panel.add(bt4);
panel.add(bt5);
panel.add(bt2);
panel.add(bt3);
panel.add(bt6);
panel.add(bt8);
BorderLayout blayout;
setLayout(blayout = new BorderLayout());
add(text, blayout.NORTH);
add(panel, blayout.CENTER);
}

// 实现接口，逻辑判断器,为运算器提供详细信息(思维中,"记忆"很重要）
public void actionPerformed(ActionEvent e) {
JButton bevent = (JButton) e.getSource();// 获得按钮事件
// 复制为全局性按钮
double result = 0;
string += bevent.getText()

;
text.setText(string);
if (string.endsWith("C")) {
string = "";
result = 0;
text.setText(String.valueOf(result));
}