c#从字节数组中检测xml编码？

using System;
using System.Text.RegularExpressions;

public class XmlEncodingDetector
{
    public static string DetectXmlEncoding(byte[] bytes)
    {
        string xmlString = System.Text.Encoding.UTF8.GetString(bytes);
        Match match = Regex.Match(xmlString, @"<\?xml.*?encoding\s*=\s*[""']?([^'"" >]+)[""']?", RegexOptions.IgnoreCase);

        if (match.Success)
        {
            return match.Groups[1].Value;
        }
        else
        {
            return null;
        }
    }
}