用eclipse开发一个计算器程序

好的，以下是实现一个简单计算器程序的步骤：

1. 创建一个 Java 项目并打开 Eclipse。
2. 在项目中创建一个名为 "Calculator" 的包。
3. 在该包中创建一个名为 "Calculator" 的 Java 类。
4. 在 Calculator 类中添加 main 方法。
5. 创建一个 JFrame 对象并将其设置为可见。
6. 添加一个 JPanel 对象到 JFrame 中。
7. 在 JPanel 中添加一个 JTextField 对象用于显示计算结果。
8. 在 JPanel 中添加多个 JButton 对象用于输入数字和操作符。
9. 给每个 JButton 添加 ActionListener。
10. 在 ActionListener 中编写相应的计算逻辑，并将结果显示在 JTextField 中。

以下是示例代码：

package Calculator;

import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Calculator {
    private JFrame frame;
    private JPanel panel;
    private JTextField textField;
    private JButton button0, button1, button2, button3, button4, button5, button6, button7, button8, button9, buttonPlus, buttonMinus, buttonMultiply, buttonDivide, buttonEquals, buttonClear;

    private String operator;
    private double firstNumber, secondNumber, result;

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Calculator window = new Calculator();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public Calculator() {
        initialize();
    }

    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 300, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setTitle("Calculator");

        panel = new JPanel();
        panel.setLayout(new GridLayout(4, 4));
        frame.getContentPane().add(panel);

        textField = new JTextField();
        panel.add(textField);

        button7 = new JButton("7");
        button7.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "7");
            }
        });
        panel.add(button7);

        button8 = new JButton("8");
        button8.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "8");
            }
        });
        panel.add(button8);

        button9 = new JButton("9");
        button9.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "9");
            }
        });
        panel.add(button9);

        buttonPlus = new JButton("+");
        buttonPlus.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                firstNumber = Double.parseDouble(textField.getText());
                operator = "+";
                textField.setText("");
            }
        });
        panel.add(buttonPlus);

        button4 = new JButton("4");
        button4.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "4");
            }
        });
        panel.add(button4);

        button5 = new JButton("5");
        button5.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "5");
            }
        });
        panel.add(button5);

        button6 = new JButton("6");
        button6.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "6");
            }
        });
        panel.add(button6);

        buttonMinus = new JButton("-");
        buttonMinus.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                firstNumber = Double.parseDouble(textField.getText());
                operator = "-";
                textField.setText("");
            }
        });
        panel.add(buttonMinus);

        button1 = new JButton("1");
        button1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "1");
            }
        });
        panel.add(button1);

        button2 = new JButton("2");
        button2.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "2");
            }
        });
        panel.add(button2);

        button3 = new JButton("3");
        button3.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "3");
            }
        });
        panel.add(button3);

        buttonMultiply = new JButton("*");
        buttonMultiply.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                firstNumber = Double.parseDouble(textField.getText());
                operator = "*";
                textField.setText("");
            }
        });
        panel.add(buttonMultiply);

        buttonClear = new JButton("C");
        buttonClear.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText("");
            }
        });
        panel.add(buttonClear);

        button0 = new JButton("0");
        button0.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textField.setText(textField.getText() + "0");
            }
        });
        panel.add(button0);

        buttonEquals = new JButton("=");
        buttonEquals.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                secondNumber = Double.parseDouble(textField.getText());
                if (operator.equals("+")) {
                    result = firstNumber + secondNumber;
                } else if (operator.equals("-")) {
                    result = firstNumber - secondNumber;
                } else if (operator.equals("*")) {
                    result = firstNumber * secondNumber;
                } else if (operator.equals("/")) {
                    result = firstNumber / secondNumber;
                }
                textField.setText(Double.toString(result));
            }
        });
        panel.add(buttonEquals);

        buttonDivide = new JButton("/");
        buttonDivide.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                firstNumber = Double.parseDouble(textField.getText());
                operator = "/";
                textField.setText("");
            }
        });
        panel.add(buttonDivide);
    }
}

这个示例程序中包括了加、减、乘、除四种基本运算，以及清除和等于两种操作。你可以根据需要添加其他操作符和功能。