Application for uploading modified Files to a FTP Server

using System;
using System.Collections;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

namespace KCommon.Net.FTP
{
	//I decide not to use UCOMIEnumVariant since I got no idea how 
	//to Marshal int back to array. As a result, I re-define the
	//IEnumVARIANT interface to simplified my work
	[	
		Guid("00020404-0000-0000-C000-000000000046"),
		InterfaceType(ComInterfaceType.InterfaceIsIUnknown)
	]
	public interface IEnumVARIANT
	{
		[MethodImpl(MethodImplOptions.PreserveSig)]
		int Next(UInt32 celt, [MarshalAs(UnmanagedType.LPArray, SizeParamIndex=0), Out]object[] rgelt, IntPtr pceltFetched);
		void Skip(UInt32 celt);
		void Reset();
		void Clone(int ppenum);
	}

	[Guid("A4C46780-499F-101B-BB78-00AA00383CBB")]
	public interface IVBCollection
	{
		[DispId(0)]
		object Item([In]ref object Index);

		[DispId(1)]
		void Add([In]ref object Item, [In, Optional]ref object Key, [In, Optional]ref object Before, [In, Optional]ref object After);

		[DispId(2)]
		Int32 Count();

		[DispId(3)]
		void Remove([In]ref object Index);

		[DispId(-4)]
		[return : MarshalAs(UnmanagedType.IUnknown)]
		object _NewEnum();
	}

	[
		Guid("A4C4671C-499F-101B-BB78-00AA00383CBB"),
		ClassInterface(ClassInterfaceType.None)
	]
	public class VbEnumableCollection : IVBCollection , IEnumVARIANT, IEnumerable
	{
		ICollection				m_collection;
		IEnumerator				m_enumerator;
		
		internal VbEnumableCollection(ICollection c)
		{
			m_collection = c;
			m_enumerator = c.GetEnumerator();
		}
		
		#region Implementation of IEnumerable
		public IEnumerator GetEnumerator()
		{
			return m_enumerator;
		}
		#endregion

		#region Implementation of IVBCollection
		public object Item(ref object Index)
		{
			throw new NotSupportedException("Method Item() not supported for VbEnumableCollection.");
		}
		public void Add(ref object Item, ref object Key, ref object Before, ref object After)
		{
			throw new NotSupportedException("Method Add() not supported for VbEnumableCollection.");
		}
		public Int32 Count()
		{
			return m_collection.Count;
		}
		public void Remove(ref object Index)
		{
			throw new NotSupportedException("Method Remove() not supported for VbEnumableCollection.");
		}
		public object _NewEnum()
		{
			return new VbEnumableCollection(m_collection);
		}
		#endregion

		#region Implementation of IEnumVariant
		public int Next(UInt32 celt, object[] rgelt, IntPtr pceltFetched)
		{
			if(pceltFetched != IntPtr.Zero)
				Marshal.WriteInt32(pceltFetched, 0);
			if(celt > 1)
				throw new NotSupportedException("Each time can fetch one item in VbCallableCollection.");
			if(m_enumerator.MoveNext()) {
				rgelt[0] = m_enumerator.Current;
				if(pceltFetched != IntPtr.Zero)
					Marshal.WriteInt32(pceltFetched, 1);
				return 0; //S_OK
			}else
				return 1; //S_FALSE
		}
		public void Skip(UInt32 celt)
		{
			throw new NotSupportedException("Method Skip() not supported in VbEnumerableCollection.");
		}
		public void Reset()
		{
			m_enumerator.Reset();
		}
		public void Clone(int ppenum)
		{
			throw new NotSupportedException("Cannot clone interface.");
		}
		#endregion
	}
}