C# SevenZip简单操作

using SevenZip;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace Test
{
    public static class ZipHelper
    {
        static bool Is64 = (IntPtr.Size == 8);
        internal const string Name32 = "7z.dll";
        internal const string Name64 = "7z64.dll";
        internal const string ZIP_FILE = "index.zip";

        static ZipHelper()
        {
            string name = Is64 ? Name64 : Name32;
            SevenZip.SevenZipExtractor.SetLibraryPath(name);
        }

        public static Stream GetSteamFrom7z(string fileName)
        {
            var stream = new MemoryStream();
            using (var tmp = new SevenZipExtractor(ZIP_FILE))
            {
                tmp.ExtractFile(fileName, stream);
            }
            stream.Position = 0;
            return stream;
        }
    }
}