用java创建一个能够计算加减法的计算器窗体

好的，以下是一个简单的Java计算器窗体，可以进行加减运算：

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

public class CalculatorUI extends JFrame implements ActionListener {
    private JTextField num1Field;
    private JTextField num2Field;
    private JTextField resultField;

    public CalculatorUI() {
        super("加减计算器");
        setLayout(new FlowLayout());

        JLabel num1Label = new JLabel("第一个数：");
        num1Field = new JTextField(10);
        add(num1Label);
        add(num1Field);

        JLabel num2Label = new JLabel("第二个数：");
        num2Field = new JTextField(10);
        add(num2Label);
        add(num2Field);

        JLabel resultLabel = new JLabel("计算结果：");
        resultField = new JTextField(10);
        resultField.setEditable(false);
        add(resultLabel);
        add(resultField);

        JButton addButton = new JButton("+");
        addButton.addActionListener(this);
        add(addButton);

        JButton subButton = new JButton("-");
        subButton.addActionListener(this);
        add(subButton);

        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setSize(250, 150);
        setLocationRelativeTo(null); // 居中显示
        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        double num1 = Double.parseDouble(num1Field.getText());
        double num2 = Double.parseDouble(num2Field.getText());

        if (e.getActionCommand().equals("+")) {
            resultField.setText(Double.toString(num1 + num2));
        } else if (e.getActionCommand().equals("-")) {
            resultField.setText(Double.toString(num1 - num2));
        }
    }

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

你可以运行该程序，会弹出一个窗口，输入两个数和点击加号或减号按钮，程序会返回计算结果。