8. 在应用程序窗体中安排两个文本框分别用来输入两个整数，三个按钮分别为“+”、“-” “clear”，一个结果标签。点击按纽“+”将两文本框的数据做加法运算；点击按钮“-”做减法运算，点击按钮“clear”清空文本框与计算结果。将运算式与结果显示在标签中。（提示：获取的文本可用Interger.parseInt()转换成整数进行计算。）用Java

这是一个简单的 Java GUI 应用程序，实现了两个整数的加减乘除运算。代码如下：

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

public class Calculator extends JFrame implements ActionListener {

    private JTextField num1Field, num2Field, resultField;
    private JButton addButton, subButton, mulButton, divButton, clearButton;

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

        // Create the input fields
        num1Field = new JTextField(10);
        num2Field = new JTextField(10);

        // Create the buttons
        addButton = new JButton("+");
        subButton = new JButton("-");
        mulButton = new JButton("*");
        divButton = new JButton("/");
        clearButton = new JButton("Clear");

        // Create the result field
        resultField = new JTextField(10);
        resultField.setEditable(false);

        // Add the components to the content pane
        Container c = getContentPane();
        c.setLayout(new FlowLayout());
        c.add(new JLabel("Number 1: "));
        c.add(num1Field);
        c.add(new JLabel("Number 2: "));
        c.add(num2Field);
        c.add(addButton);
        c.add(subButton);
        c.add(mulButton);
        c.add(divButton);
        c.add(clearButton);
        c.add(new JLabel("Result: "));
        c.add(resultField);

        // Add action listeners to the buttons
        addButton.addActionListener(this);
        subButton.addActionListener(this);
        mulButton.addActionListener(this);
        divButton.addActionListener(this);
        clearButton.addActionListener(this);

        // Set the size and make the window visible
        setSize(300, 150);
        setVisible(true);
    }

    // Handle button clicks
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == addButton) {
            int num1 = Integer.parseInt(num1Field.getText());
            int num2 = Integer.parseInt(num2Field.getText());
            int result = num1 + num2;
            resultField.setText(Integer.toString(result));
        } else if (e.getSource() == subButton) {
            int num1 = Integer.parseInt(num1Field.getText());
            int num2 = Integer.parseInt(num2Field.getText());
            int result = num1 - num2;
            resultField.setText(Integer.toString(result));
        } else if (e.getSource() == mulButton) {
            int num1 = Integer.parseInt(num1Field.getText());
            int num2 = Integer.parseInt(num2Field.getText());
            int result = num1 * num2;
            resultField.setText(Integer.toString(result));
        } else if (e.getSource() == divButton) {
            int num1 = Integer.parseInt(num1Field.getText());
            int num2 = Integer.parseInt(num2Field.getText());
            int result = num1 / num2;
            resultField.setText(Integer.toString(result));
        } else if (e.getSource() == clearButton) {
            num1Field.setText("");
            num2Field.setText("");
            resultField.setText("");
        }
    }

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

运行程序后，会弹出一个窗口，可以输入两个整数，然后点击加、减、乘、除按钮进行运算，点击 Clear 按钮可以清空输入和结果。