Use fixed size buffers:
[StructLayout(LayoutKind.Explicit)]
unsafe struct headerUnion // 2048 bytes in header
{
[FieldOffset(0)]
public fixed byte headerBytes[2048];
[FieldOffset(0)]
public headerLayout header;
}
Alternativ you can just use the struct and read it with the following extension method:
private static T ReadStruct<T>(this BinaryReader reader)
where T : struct
{
Byte[] buffer = new Byte[Marshal.SizeOf(typeof(T))];
reader.Read(buffer, 0, buffer.Length);
GCHandle handle = default(GCHandle);
try
{
handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
return (T)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(T));
}
finally
{
if (handle.IsAllocated)
handle.Free();
}
}