利用java创建一个计算器程序窗口

可以使用Java Swing库创建一个简单的计算器程序窗口。以下是一个示例代码：

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

public class Calculator extends JFrame implements ActionListener {
    private JTextField displayField;
    private JButton[] numberButtons;
    private JButton[] operatorButtons;
    private JButton clearButton, equalsButton;

    private double operand1, operand2;
    private String operator;

    public Calculator() {
        super("Calculator");

        displayField = new JTextField(16);
        displayField.setEditable(false);
        add(displayField, BorderLayout.NORTH);

        JPanel buttonPanel = new JPanel(new GridLayout(4, 4));

        numberButtons = new JButton[10];
        for (int i = 0; i < 10; i++) {
            numberButtons[i] = new JButton(Integer.toString(i));
            numberButtons[i].addActionListener(this);
            buttonPanel.add(numberButtons[i]);
        }

        operatorButtons = new JButton[6];
        operatorButtons[0] = new JButton("+");
        operatorButtons[1] = new JButton("-");
        operatorButtons[2] = new JButton("*");
        operatorButtons[3] = new JButton("/");
        operatorButtons[4] = new JButton(".");
        operatorButtons[5] = new JButton("C");

        for (int i = 0; i < 6; i++) {
            operatorButtons[i].addActionListener(this);
            buttonPanel.add(operatorButtons[i]);
        }

        add(buttonPanel, BorderLayout.CENTER);

        equalsButton = new JButton("=");
        equalsButton.addActionListener(this);
        clearButton = new JButton("C");
        clearButton.addActionListener(this);

        JPanel bottomPanel = new JPanel();
        bottomPanel.add(clearButton);
        bottomPanel.add(equalsButton);
        add(bottomPanel, BorderLayout.SOUTH);

        pack();
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();

        if (command.equals("+") || command.equals("-") || command.equals("*") || command.equals("/")) {
            operand1 = Double.parseDouble(displayField.getText());
            operator = command;
            displayField.setText("");
        } else if (command.equals(".")) {
            if (!displayField.getText().contains(".")) {
                displayField.setText(displayField.getText() + ".");
            }
        } else if (command.equals("=")) {
            operand2 = Double.parseDouble(displayField.getText());
            double result = 0.0;
            if (operator.equals("+")) {
                result = operand1 + operand2;
            } else if (operator.equals("-")) {
                result = operand1 - operand2;
            } else if (operator.equals("*")) {
                result = operand1 * operand2;
            } else if (operator.equals("/")) {
                result = operand1 / operand2;
            }
            displayField.setText(Double.toString(result));
        } else if (command.equals("C")) {
            displayField.setText("");
        } else {
            displayField.setText(displayField.getText() + command);
        }
    }

    public static void main(String[] args) {
        Calculator calculator = new Calculator();
        calculator.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

这个程序创建了一个带有数字、运算符、清除和等于按钮的简单计算器窗口。用户可以按下数字和运算符按钮，然后按下等于按钮以计算结果。