Someone

using System;
using System.Runtime.InteropServices;

namespace MarshalCopyTester
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	public class Tester
	{

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main() 
		{
			DoTest();
		}

		private static  void DoTest()
		{
			byte[]      imagebits = new byte[] {1,2,3,4};
			IntPtr ptr;

			
			Console.WriteLine("{0} {1} {2} {3}",imagebits[0],imagebits[1],imagebits[2],imagebits[3]);
			
			ptr = Marshal.AllocHGlobal(4);
			Marshal.Copy(imagebits, 0, ptr, imagebits.Length);

			Console.WriteLine("{0} {1} {2} {3}",Marshal.ReadByte(ptr),Marshal.ReadByte((IntPtr)(ptr.ToInt32()+Marshal.SizeOf(typeof(byte))) ) 
				,Marshal.ReadByte((IntPtr)(ptr.ToInt32()+2*Marshal.SizeOf(typeof(byte))) ),
				Marshal.ReadByte((IntPtr)(ptr.ToInt32()+3*Marshal.SizeOf(typeof(byte))) )
				);

			// Copy from source to managed

			Marshal.Copy(ptr, imagebits, 0, imagebits.Length);
			Console.WriteLine("{0} {1} {2} {3}",imagebits[0],imagebits[1],imagebits[2],imagebits[3]);

 

			// Copy from managed to dest

			Marshal.Copy(imagebits, 0, ptr, imagebits.Length);
			Console.WriteLine("{0} {1} {2} {3}",Marshal.ReadByte(ptr),Marshal.ReadByte((IntPtr)(ptr.ToInt32()+Marshal.SizeOf(typeof(byte))) ) 
				,Marshal.ReadByte((IntPtr)(ptr.ToInt32()+2*Marshal.SizeOf(typeof(byte))) ),
				Marshal.ReadByte((IntPtr)(ptr.ToInt32()+3*Marshal.SizeOf(typeof(byte))) )
				);
		}
	}
}