【Java】Java使用Swing模拟电脑计算器

以下是一个简化的Java Swing计算器示例，仅包含基本的加减乘除功能。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
public class CalculatorGUI extends JFrame implements ActionListener {
    private JTextField display;
    private double total;
    private double current;
    private String operator;
    private boolean start;
 
    public CalculatorGUI() {
        super("计算器");
        start = true;
        initUI();
    }
 
    private void initUI() {
        GridBagLayout gridbag = new GridBagLayout();
        GridBagConstraints c = new GridBagConstraints();
        display = new JTextField(20);
        display.setEditable(false);
        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridwidth = GridBagConstraints.REMAINDER;
        gridbag.setConstraints(display, c);
        add(display);
 
        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(4, 4));
 
        addButton("7", panel);
        addButton("8", panel);
        addButton("9", panel);
        addButton("+", panel);
 
        addButton("4", panel);
        addButton("5", panel);
        addButton("6", panel);
        addButton("-", panel);
 
        addButton("1", panel);
        addButton("2", panel);
        addButton("3", panel);
        addButton("*", panel);
 
        addButton("0", panel);
        addButton(".", panel);
        JButton equalButton = new JButton("=");
        equalButton.setActionCommand("equal");
        equalButton.addActionListener(this);
        panel.add(equalButton);
        addButton("/", panel);
 
        c.gridwidth = GridBagConstraints.REMAINDER;
        gridbag.setConstraints(panel, c);
        add(panel);
 
        setSize(300, 300);
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
 
    private void addButton(String label, Container panel) {
        JButton button = new JButton(label);
        button.addActionListener(this);
        panel.add(button);
    }
 
    @Override
    public void actionPerformed(ActionEvent event) {
        String input = event.getActionCommand();
        if (start) {
            display.setText("");
            start = false;
        }
        if (input.equals("+")) {
            operator = input;
            current = Double.parseDouble(display.getText());
        } else if (input.equals("-")) {
            operator = input;