Cannot take the address or size of a variable of a managed type

[J?n Sveinsson]

Hello everyone

I have been trying to read and write struct to binary files, I'm using
to functions to convert the struct to bytes and bytes to struct, I
always receive the following error

C:\Documents and Settings\jon.JONHS-LAP\My Documents\Visual Studio
Projects\StructTest\Class1.cs(100): Cannot take the address or size of
a variable of a managed type ('StructTest.test')

Here is my code, what is I doing wrong here.
using System;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.InteropServices;
namespace StructTest
{

[StructLayout(LayoutKind.Sequential, Pack=1)]
public struct test
{
[MarshalAs(UnmanagedType.I4, SizeConst=3)]
public int[] local;
public int local1;
public int local2;
}
class Class1
{

[STAThread]
static unsafe void Main(string[] args)
{

int[] y = new int[3];

y.SetValue(12,0);
y.SetValue(12,1);
y.SetValue(12,2);

test h = new test();
h.local = y;
h.local1 = 20;
h.local2 = 30;

FileStream fs = new FileStream("Test5.txt",FileMode.Open);

int tr = Marshal.SizeOf(h);

byte[] array = new byte[tr];

array = YourStructToBytes(h);

test g = new test();

g = BytesToYourStruct(array);

fs.Read(array,0,tr);

}
static unsafe byte[] YourStructToBytes( test s )
{
byte[] arr = new byte[ Marshal.SizeOf(s) ];
fixed( byte* parr = arr )
{
*((test*)parr) = s;//Cannot take the address or size of a
variable of a managed type
}
return arr;
}

static unsafe test BytesToYourStruct( byte[] arr )
{
if( arr.Length < sizeof(test) )
throw new ArgumentException();

test s;
fixed( byte* parr = arr )
{ s = *((test*)parr); }
return s;
}
}
}