System.IO.Compression.ZipStorer.GetFileOffset C# (CSharp) Méthode

        private uint GetFileOffset(uint _headerOffset)
        {
            byte[] buffer = new byte[2];

            this.ZipFileStream.Seek(_headerOffset + 26, SeekOrigin.Begin);
            this.ZipFileStream.Read(buffer, 0, 2);
            ushort filenameSize = BitConverter.ToUInt16(buffer, 0);
            this.ZipFileStream.Read(buffer, 0, 2);
            ushort extraSize = BitConverter.ToUInt16(buffer, 0);

            return (uint)(30 + filenameSize + extraSize + _headerOffset);
        }