diff --git a/BaseConverter.java b/BaseConverter.java
index e793c7f..41826fc 100644
--- a/BaseConverter.java
+++ b/BaseConverter.java
@@ -2,11 +2,11 @@ import javax.swing.*;
 import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
-import java.util.Scanner;
+import java.util.Arrays;
+import java.util.List;
 
 public class BaseConverter {
 
-    // 字符数组，用于表示大于9的数字
     private static final char[] DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
 
     /**
@@ -27,6 +27,7 @@ public class BaseConverter {
         }
         return result;
     }
+
     /**
      * 将十进制整数转换为目标进制的字符串
      *
@@ -47,6 +48,7 @@ public class BaseConverter {
 
         return result.toString();
     }
+
     /**
      * 将任意进制的数转换为另一个任意进制的数
      *
@@ -73,8 +75,8 @@ public class BaseConverter {
     public static class BaseConverterGUI extends JFrame {
 
         private JTextField inputField;
-        private JTextField sourceBaseField;
-        private JTextField targetBaseField;
+        private JComboBox<Integer> sourceBaseBox;
+        private JComboBox<Integer> targetBaseBox;
         private JButton convertButton;
         private JLabel resultLabel;
 
@@ -83,32 +85,76 @@ public class BaseConverter {
             setSize(400, 200);
             setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             setLocationRelativeTo(null); // 居中显示
-            setLayout(new GridLayout(5, 2));
+            setLayout(new GridBagLayout());
+
+            GridBagConstraints gbc = new GridBagConstraints();
 
             // 输入框
+            gbc.gridx = 0;
+            gbc.gridy = 0;
+            gbc.anchor = GridBagConstraints.EAST;
+            gbc.insets = new Insets(5, 5, 5, 5);
+            add(new JLabel("输入数据（例如 A1）:"), gbc);
+
+            gbc.gridx = 1;
+            gbc.gridy = 0;
+            gbc.fill = GridBagConstraints.HORIZONTAL;
+            gbc.weightx = 1;
+            gbc.anchor = GridBagConstraints.WEST;
             inputField = new JTextField();
-            add(new JLabel("输入数据（例如 A1）:"));
-            add(inputField);
-
-            // 源进制输入框
-            sourceBaseField = new JTextField();
-            add(new JLabel("源进制数（例如 16）:"));
-            add(sourceBaseField);
-
-            // 目标进制输入框
-            targetBaseField = new JTextField();
-            add(new JLabel("目标进制数（例如 2）:"));
-            add(targetBaseField);
+            add(inputField, gbc);
+
+            // 源进制下拉菜单
+            gbc.gridx = 0;
+            gbc.gridy = 1;
+            gbc.fill = GridBagConstraints.NONE;
+            gbc.weightx = 0;
+            gbc.anchor = GridBagConstraints.EAST;
+            add(new JLabel("源进制数（例如 16）:"), gbc);
+
+            gbc.gridx = 1;
+            gbc.gridy = 1;
+            gbc.fill = GridBagConstraints.HORIZONTAL;
+            gbc.weightx = 1;
+            gbc.anchor = GridBagConstraints.WEST;
+            List<Integer> bases = Arrays.asList(2, 4, 8, 10, 16, 32);
+            sourceBaseBox = new JComboBox<>(bases.toArray(new Integer[0]));
+            add(sourceBaseBox, gbc);
+
+            // 目标进制下拉菜单
+            gbc.gridx = 0;
+            gbc.gridy = 2;
+            gbc.fill = GridBagConstraints.NONE;
+            gbc.weightx = 0;
+            gbc.anchor = GridBagConstraints.EAST;
+            add(new JLabel("目标进制数（例如 2）:"), gbc);
+
+            gbc.gridx = 1;
+            gbc.gridy = 2;
+            gbc.fill = GridBagConstraints.HORIZONTAL;
+            gbc.weightx = 1;
+            gbc.anchor = GridBagConstraints.WEST;
+            targetBaseBox = new JComboBox<>(bases.toArray(new Integer[0]));
+            add(targetBaseBox, gbc);
 
             // 转换按钮
+            gbc.gridx = 1;
+            gbc.gridy = 3;
+            gbc.fill = GridBagConstraints.NONE;
+            gbc.weightx = 0;
+            gbc.anchor = GridBagConstraints.CENTER;
             convertButton = new JButton("转换");
-            add(new JLabel());
-            add(convertButton);
+            add(convertButton, gbc);
 
             // 结果标签
+            gbc.gridx = 0;
+            gbc.gridy = 4;
+            gbc.gridwidth = 2;
+            gbc.fill = GridBagConstraints.HORIZONTAL;
+            gbc.weightx = 1;
+            gbc.anchor = GridBagConstraints.LINE_START;
             resultLabel = new JLabel("转换结果：");
-            add(new JLabel());
-            add(resultLabel);
+            add(resultLabel, gbc);
 
             // 添加监听器到按钮
             convertButton.addActionListener(new ActionListener() {
@@ -116,8 +162,8 @@ public class BaseConverter {
                 public void actionPerformed(ActionEvent e) {
                     try {
                         String input = inputField.getText().toUpperCase();
-                        int sourceBase = Integer.parseInt(sourceBaseField.getText());
-                        int targetBase = Integer.parseInt(targetBaseField.getText());
+                        int sourceBase = (Integer) sourceBaseBox.getSelectedItem();
+                        int targetBase = (Integer) targetBaseBox.getSelectedItem();
                         String result = convertBase(input, sourceBase, targetBase);
                         resultLabel.setText("转换结果：" + result);
                     } catch (Exception ex) {
@@ -126,8 +172,8 @@ public class BaseConverter {
                 }
             });
 
+            pack(); // 自动调整大小以适应所有组件
             setVisible(true);
         }
     }
-
 }
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