如何从Active Directory中获取用户头像？

using System;
using System.DirectoryServices;

public class ActiveDirectoryHelper
{
    public byte[] GetUserThumbnailPhoto(string username)
    {
        // 连接到Active Directory
        DirectoryEntry entry = new DirectoryEntry("LDAP://your-domain-controller");
        entry.Username = "your-username";
        entry.Password = "your-password";

        // 搜索用户对象
        DirectorySearcher searcher = new DirectorySearcher(entry);
        searcher.Filter = $"(&(objectClass=user)(sAMAccountName={username}))";
        SearchResult result = searcher.FindOne();

        if (result != null)
        {
            // 获取用户头像属性
            DirectoryEntry userEntry = result.GetDirectoryEntry();
            if (userEntry.Properties.Contains("thumbnailPhoto"))
            {
                byte[] thumbnailPhoto = (byte[])userEntry.Properties["thumbnailPhoto"].Value;
                return thumbnailPhoto;
            }
        }

        return null;
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        ActiveDirectoryHelper adHelper = new ActiveDirectoryHelper();
        byte[] thumbnailPhoto = adHelper.GetUserThumbnailPhoto("john.doe");

        if (thumbnailPhoto != null)
        {
            // 将头像保存为文件或进行其他操作
            // ...
        }
    }
}