Fixed size structure in C#

[niketan]

Hello,
How can I define fixed size of structure in c#..
e.g.

struct xyz{
char localc[12];
short localshort;
};

I had made a c# structure like this 
[StructLayout(LayoutKind.Sequential,  Pack = 2,CharSet=CharSet.Ansi, Size = 14)]
struct xyz{
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
public char[] localc;
short localshort;
}

xyz abc = new xyz();

Here i am not able to get the sizeof abc as 14 ..and got error while mashal.sizeof(abc);
How should i preallocate memory of size of structure ?
I can easily does that in c/c++ by just declaring it .. how to make this possible in c#?
and i can initialise the structure using memset in c .. whats its alternative in c#?

It will be helpful to get the solution

[VIeditorlover]

I am not sure about that, but unsafe could do the trick...

[__avd]

Import - using System.Runtime.InteropServices;

xyz p = new xyz();
 MessageBox.Show(Marshal.SizeOf(p).ToString());

Read this http://msdn.microsoft.com/en-us/library/zycewsya(VS.80).aspx

[sknake]

In .NET the char data type is is 16bit, most other languages it is 8bit. You will also need to watch out for that.

[__avd]

Because of this unmanaged attribute a size of char is 8 bits.

[StructLayout(LayoutKind.Sequential, Pack = 2, CharSet = CharSet.Ansi, Size = 14)]
        struct xyz
        {
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
            public char[] localc;
            short localshort;
        }
  ...
  ...
xyz p = new xyz();
int size=Marshal.SizeOf(p);
..

So the size of struct is 14 bytes.