第一次修改

src/xzk/Calculator.java

@@ -0,0 +1,127 @@
+package xzk;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class Calculator extends JFrame implements ActionListener {
+
+    private JTextField num1Field, num2Field, resultField;
+    private JComboBox<String> operatorBox;
+
+    public Calculator() {
+        // 设置窗口标题
+        super("简单计算器");
+
+        // 设置布局
+        setLayout(new BorderLayout());
+
+        // 创建面板
+        JPanel inputPanel = new JPanel(new GridBagLayout());
+        GridBagConstraints gbc = new GridBagConstraints();
+        gbc.insets = new Insets(5, 5, 5, 5); // 设置组件之间的间距
+
+        // 创建输入字段和标签
+        gbc.gridx = 0;
+        gbc.gridy = 0;
+        inputPanel.add(new JLabel("第一个数字:"), gbc);
+        gbc.gridx = 1;
+        num1Field = new JTextField(10);
+        inputPanel.add(num1Field, gbc);
+
+        gbc.gridy = 1;
+        gbc.gridx = 0;
+        inputPanel.add(new JLabel("第二个数字:"), gbc);
+        gbc.gridx = 1;
+        num2Field = new JTextField(10);
+        inputPanel.add(num2Field, gbc);
+
+        gbc.gridy = 2;
+        gbc.gridx = 0;
+        inputPanel.add(new JLabel("操作符:"), gbc);
+        gbc.gridx = 1;
+        operatorBox = new JComboBox<>(new String[]{"+", "-", "*", "/", "%"});
+        inputPanel.add(operatorBox, gbc);
+
+        gbc.gridy = 3;
+        gbc.gridx = 0;
+        inputPanel.add(new JLabel("结果:"), gbc);
+        gbc.gridx = 1;
+        resultField = new JTextField(10);
+        resultField.setEditable(false);
+        inputPanel.add(resultField, gbc);
+
+        // 创建计算按钮
+        JButton calculateButton = new JButton("计算");
+        gbc.gridy = 4;
+        gbc.gridx = 0;
+        gbc.gridwidth = 2;
+        gbc.fill = GridBagConstraints.HORIZONTAL;
+        inputPanel.add(calculateButton, gbc);
+
+        // 添加事件监听器
+        calculateButton.addActionListener(this);
+
+        // 设置面板背景色
+        inputPanel.setBackground(Color.LIGHT_GRAY);
+
+        // 将面板添加到窗口
+        add(inputPanel, BorderLayout.CENTER);
+
+        // 设置窗口属性
+        setSize(400, 300);
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setLocationRelativeTo(null); // 窗口居中显示
+        setVisible(true);
+    }
+
+    @Override
+    public void actionPerformed(ActionEvent e) {
+        try {
+            double num1 = Double.parseDouble(num1Field.getText());
+            double num2 = Double.parseDouble(num2Field.getText());
+            String operator = (String) operatorBox.getSelectedItem();
+            double result;
+
+            switch (operator) {
+                case "+":
+                    result = num1 + num2;
+                    break;
+                case "-":
+                    result = num1 - num2;
+                    break;
+                case "*":
+                    result = num1 * num2;
+                    break;
+                case "/":
+                    if (num2 != 0) {
+                        result = num1 / num2;
+                    } else {
+                        JOptionPane.showMessageDialog(this, "错误：除数不能为零");
+                        return;
+                    }
+                    break;
+                case "%":
+                    if (num2 != 0) {
+                        result = num1 % num2;
+                    } else {
+                        JOptionPane.showMessageDialog(this, "错误：除数不能为零");
+                        return;
+                    }
+                    break;
+                default:
+                    JOptionPane.showMessageDialog(this, "无效的操作符!");
+                    return;
+            }
+
+            resultField.setText(String.format("%.2f", result));
+        } catch (NumberFormatException ex) {
+            JOptionPane.showMessageDialog(this, "请输入有效的数字");
+        }
+    }
+
+    public static void main(String[] args) {
+        new Calculator();
+    }
+}