UnmanagedType.LPArray in structure

[mrvetal]

Hello

My programm receives array of bytes over SSL from Delphi program.
I convert it into structure and have en error:
Type 'SetOrder' cannot be marshaled as an unmanaged structure; no meaningful size or offset can be computed

Delphi:

TTLVHADPrefix = packed record
  ProtocolID: TProtocolID;
  Version: Byte;
end;

TTLVHAD = packed record
  Prefix: TTLVHADPrefix;
  Len: DWORD;
  TermID: TTermID;
  OperCode: WORD;
end;

TTLV602 = packed record
  Header: TTLVHAD;
 [B][U] AccNumLen: WORD;
  AccNum: array of Char;[/U][/B]
  AccType: Char;
  Status: Char;
end;

My C#

        [StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Ansi)]
        public struct TlvHad
        {
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 3)]
            public Char[] tlv;          
            public Byte protocolVer; 
        }

        [StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Ansi)]
        public struct HeaderQry
        {
            public TlvHad prefix; 
            public UInt32 len;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
            public Char[] termID; 
            public UInt16 operCode;
        }

       [StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Ansi)]
        public struct SetOrder
        {
            public HeaderQry headerQry; 
[B][U]            public UInt16 AccNumLen;    
            [MarshalAs(UnmanagedType.LPArray, SizeParamIndex=12)]
            public Char[] AccNum; [/U][/B]      
            public Char Type;           
            public Char Status;         
        }

        public static object Deserialize(byte[] rawdatas, Type anytype)
        {
[B][U]ERROR THIS[/U][/B]  int rawsize = Marshal.SizeOf(anytype);
            if (rawsize > rawdatas.Length)
                return null;
            GCHandle handle = GCHandle.Alloc(rawdatas, GCHandleType.Pinned);
            IntPtr buffer = handle.AddrOfPinnedObject();
            object retobj = Marshal.PtrToStructure(buffer, anytype);
            handle.Free();
            return retobj;
        }

[bvrwoo]

I am not sure that you can marshal the size of anytype because you can only marshal structures I believe do the CLR reallocating the heap which you cannot control. Thus is the same reason you cannot use the fixed keyword on a class type to point to. In cases like this it is far better to use C++/CLI.