[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    internal struct GuidStruct
    {
        internal UInt32 Data1;
        internal UInt16 Data2;
        internal UInt16 Data3;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
        internal byte[] Data4;

        internal GuidStruct Initialize()
        {
        Data4 = new byte[8];
          return this;
        }

        internal GuidStruct Initialize(string guid)
        {
        Data4 = new byte[8];
        ConvertirToGuidStruct(guid);
        return this;
        }

        internal void ConvertToGuidStruct(string guid)
        {
        string[] guidTab = guid.Split(new char[] { ':', '-' });
        if (guidTab.Length == 5)
        {
            this.Data1 = Convert.ToUInt32(guidTab[0], 16);
            this.Data2 = Convert.ToUInt16(guidTab[1], 16);
            this.Data3 = Convert.ToUInt16(guidTab[2], 16);
            byte[] data4Part1 = BitConverter.GetBytes(Convert.ToInt16(guidTab[3], 16));
            byte[] data4Part2 = BitConverter.GetBytes(Convert.ToInt64(guidTab[4], 16));

            if (data4Part1.Length == 2 && data4Part2.Length == 8)
            {
            this.Data4[0] = data4Part1[0];
            this.Data4[1] = data4Part1[1];
            this.Data4[2] = data4Part2[0];
            this.Data4[3] = data4Part2[1];
            this.Data4[4] = data4Part2[2];
            this.Data4[5] = data4Part2[3];
            this.Data4[6] = data4Part2[4];
            this.Data4[7] = data4Part2[5];
            }
        }
        }

        internal string ConvertToString()
        {
        string guid;

        guid = Data1.ToString("x").PadLeft(8, '0');
        guid += "-" + Data2.ToString("x").PadLeft(4, '0');
        guid += "-" + Data3.ToString("x").PadLeft(4, '0');
        guid += "-" + BitConverter.ToInt16(new byte[] { Data4[0], Data4[1] }, 0).ToString("x");
        guid += "-" + BitConverter.ToInt64(new byte[] { Data4[2], Data4[3], Data4[4], Data4[5], Data4[6], Data4[7], 0, 0 }, 0).ToString("x");
        return guid;
        }
    }