java图形页面计算器

以下是一个简单的 Java 图形页面计算器的示例代码：

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

public class Calculator extends JFrame implements ActionListener {

    private JTextField textField;
    private JButton addButton, subtractButton, multiplyButton, divideButton, equalsButton, clearButton;
    private JPanel buttonPanel;

    private double firstNumber = 0.0;
    private double secondNumber = 0.0;
    private String operator = "";

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

        // Create text field
        textField = new JTextField(20);
        textField.setEditable(false);

        // Create buttons
        addButton = new JButton("+");
        subtractButton = new JButton("-");
        multiplyButton = new JButton("*");
        divideButton = new JButton("/");
        equalsButton = new JButton("=");
        clearButton = new JButton("C");

        // Add action listeners to buttons
        addButton.addActionListener(this);
        subtractButton.addActionListener(this);
        multiplyButton.addActionListener(this);
        divideButton.addActionListener(this);
        equalsButton.addActionListener(this);
        clearButton.addActionListener(this);

        // Add buttons to panel
        buttonPanel = new JPanel();
        buttonPanel.setLayout(new GridLayout(4,2));
        buttonPanel.add(addButton);
        buttonPanel.add(subtractButton);
        buttonPanel.add(multiplyButton);
        buttonPanel.add(divideButton);
        buttonPanel.add(equalsButton);
        buttonPanel.add(clearButton);

        // Add components to frame
        add(textField, BorderLayout.NORTH);
        add(buttonPanel, BorderLayout.CENTER);

        // Set frame properties
        setSize(300, 200);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

    public void actionPerformed(ActionEvent event) {
        String buttonText = event.getActionCommand();

        if(buttonText.equals("+")) {
            operator = "+";
            firstNumber = Double.parseDouble(textField.getText());
            textField.setText("");
        } else if(buttonText.equals("-")) {
            operator = "-";
            firstNumber = Double.parseDouble(textField.getText());
            textField.setText("");
        } else if(buttonText.equals("*")) {
            operator = "*";
            firstNumber = Double.parseDouble(textField.getText());
            textField.setText("");
        } else if(buttonText.equals("/")) {
            operator = "/";
            firstNumber = Double.parseDouble(textField.getText());
            textField.setText("");
        } else if(buttonText.equals("=")) {
            secondNumber = Double.parseDouble(textField.getText());

            if(operator.equals("+")) {
                textField.setText(Double.toString(firstNumber + secondNumber));
            } else if(operator.equals("-")) {
                textField.setText(Double.toString(firstNumber - secondNumber));
            } else if(operator.equals("*")) {
                textField.setText(Double.toString(firstNumber * secondNumber));
            } else if(operator.equals("/")) {
                textField.setText(Double.toString(firstNumber / secondNumber));
            }
        } else if(buttonText.equals("C")) {
            textField.setText("");
        }
    }

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

该计算器支持加、减、乘、除四种基本运算，以及清除文本框内容。用户可以通过点击按钮输入数字和运算符，计算结果将显示在文本框中。