vs2015判断rvt版本

using System;
using System.Text;
using System.IO;
using System.Text.RegularExpressions;

namespace ReadRvt
{
    class Program
    {
        static void Main(string[] args)
        {
            string ss = GetRevitVision("E:/测试项目/mine/xx.rvt");
            Console.WriteLine("REVIT文件版本:"+ ss);
            Console.ReadKey();

        }
        public static string GetRevitVision(string path)
        {
            string revitVision = null;
            FileStream stream = new FileStream(path, FileMode.Open);
            int size = 1024 * 1024;
            byte[] bytes = new byte[size];
            while (stream.Read(bytes, 0, size) > 0)
            {
                string str = Encoding.Unicode.GetString(bytes);

                string pattern = @"Autodesk Revit \d{4}";
                var match = Regex.Match(str, pattern);
                if (match.Success)
                {
                    revitVision = match.Value.Substring(match.Length - 4, 4);
                    break;
                }
            }
            return revitVision;
        }
    }
}