使用java实现一个计算器页面

好的，以下是一个简单的使用 Java 实现计算器页面的示例代码：

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Calculator implements ActionListener {

    private JFrame frame;
    private JPanel panel;
    private JTextField output;
    private JButton[] buttons;
    private String[] labels = { "7", "8", "9", "/", "4", "5", "6", "*", "1", "2", "3", "-", "0", ".", "=", "+" };
    private double num1 = 0, num2 = 0, result = 0;
    private char op = ' ';

    public Calculator() {
        frame = new JFrame("Calculator");
        panel = new JPanel();
        output = new JTextField("");
        buttons = new JButton[16];

        output.setEditable(false);
        output.setHorizontalAlignment(JTextField.RIGHT);

        panel.setLayout(new GridLayout(4, 4));

        for (int i = 0; i < 16; i++) {
            buttons[i] = new JButton(labels[i]);
            buttons[i].addActionListener(this);
            panel.add(buttons[i]);
        }

        frame.getContentPane().add(output, BorderLayout.NORTH);
        frame.getContentPane().add(panel, BorderLayout.CENTER);

        frame.pack();
        frame.setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        Object source = e.getSource();

        for (int i = 0; i < 16; i++) {
            if (source == buttons[i]) {
                if (labels[i].matches("[0-9]")) {
                    if (op == ' ') {
                        num1 = num1 * 10 + Integer.parseInt(labels[i]);
                        output.setText(String.valueOf(num1));
                    } else {
                        num2 = num2 * 10 + Integer.parseInt(labels[i]);
                        output.setText(String.valueOf(num2));
                    }
                } else if (labels[i].equals(".")) {
                    if (op == ' ') {
                        num1 = Double.parseDouble(output.getText());
                        output.setText(output.getText() + ".");
                    } else {
                        num2 = Double.parseDouble(output.getText());
                        output.setText(output.getText() + ".");
                    }
                } else if (labels[i].matches("[/+*-]")) {
                    op = labels[i].charAt(0);
                } else if (labels[i].equals("=")) {
                    if (op == '+') {
                        result = num1 + num2;
                    } else if (op == '-') {
                        result = num1 - num2;
                    } else if (op == '*') {
                        result = num1 * num2;
                    } else if (op == '/') {
                        result = num1 / num2;
                    }
                    op = ' ';
                    num1 = result;
                    num2 = 0;
                    output.setText(String.valueOf(result));
                }
            }
        }
    }

    public static void main(String[] args) {
        new Calculator();
    }
}

这个程序使用 JFrame 和 JPanel 实现计算器页面，其中包含一个 JTextField 用于显示计算结果，以及 16 个 JButton 用于接收用户输入的数字和运算符。每当用户点击一个按钮时，程序通过 actionPerformed 方法进行相应的处理，最终实现计算器的基本功能。