JAVA编程实现一个加减法计算器。可以使用鼠标来完成加减法运算。GUI界面细致精准

以下是一个Java实现加减法计算器的示例代码：

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

public class Calculator implements ActionListener {
    JFrame frame;
    JTextField textField;
    JButton[] numberButtons = new JButton[10];
    JButton[] functionButtons = new JButton[5];
    JButton addButton, subButton;
    JPanel panel;

    double num1 = 0, num2 = 0, result = 0;
    char operator;

    public Calculator() {
        frame = new JFrame("Calculator");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 400);
        frame.setLayout(null);

        textField = new JTextField();
        textField.setBounds(50, 25, 300, 50);
        textField.setEditable(false);

        addButton = new JButton("+");
        subButton = new JButton("-");
        functionButtons[0] = addButton;
        functionButtons[1] = subButton;

        for (int i = 0; i < 10; i++) {
            numberButtons[i] = new JButton(String.valueOf(i));
        }

        panel = new JPanel();
        panel.setBounds(50, 100, 300, 250);
        panel.setLayout(new GridLayout(4, 4));

        panel.add(numberButtons[1]);
        panel.add(numberButtons[2]);
        panel.add(numberButtons[3]);
        panel.add(addButton);

        panel.add(numberButtons[4]);
        panel.add(numberButtons[5]);
        panel.add(numberButtons[6]);
        panel.add(subButton);

        panel.add(numberButtons[7]);
        panel.add(numberButtons[8]);
        panel.add(numberButtons[9]);
        panel.add(functionButtons[2]);

        panel.add(functionButtons[3]);
        panel.add(numberButtons[0]);
        panel.add(functionButtons[4]);
        panel.add(functionButtons[5]);

        for (int i = 0; i < 10; i++) {
            numberButtons[i].addActionListener(this);
        }

        for (int i = 0; i < 5; i++) {
            functionButtons[i].addActionListener(this);
        }

        frame.add(textField);
        frame.add(panel);
        frame.setVisible(true);
    }

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

    @Override
    public void actionPerformed(ActionEvent e) {
        for (int i = 0; i < 10; i++) {
            if (e.getSource() == numberButtons[i]) {
                textField.setText(textField.getText().concat(String.valueOf(i)));
            }
        }

        if (e.getSource() == addButton) {
            num1 = Double.parseDouble(textField.getText());
            operator = '+';
            textField.setText("");
        }

        if (e.getSource() == subButton) {
            num1 = Double.parseDouble(textField.getText());
            operator = '-';
            textField.setText("");
        }

        if (e.getSource() == functionButtons[2]) {
            num2 = Double.parseDouble(textField.getText());

            switch (operator) {
                case '+':
                    result = num1 + num2;
                    break;

                case '-':
                    result = num1 - num2;
                    break;
            }

            textField.setText(String.valueOf(result));
        }

        if (e.getSource() == functionButtons[3]) {
            textField.setText("");
        }

        if (e.getSource() == functionButtons[4]) {
            String currentText = textField.getText();

            if (currentText.length() > 0) {
                textField.setText(currentText.substring(0, currentText.length() - 1));
            }
        }
    }
}

在这个实现中，我们使用了Java Swing库来创建GUI界面，其中包括一个文本框和数字、运算符按钮。我们还实现了一个ActionListener接口，在用户点击按钮时处理相应的操作，包括将数字添加到文本框中、记录第一个数字和运算符、计算结果等等。

请注意，这只是一个简单的示例代码，可能需要进行更多的测试和优化。