C# WinForms Application Full Integration with HTMLHelp ( .chm ) - Help Topics, Context Sensitive Help, and Tooltips

using System;
using System.IO;
using Microsoft.VisualStudio.OLE.Interop;


namespace WinHelpLib
{
    class IStreamEx : Stream 
    {
        IStream iStream;
        long lSize = 0;

        public IStreamEx(IStream iStr) 
        { 
            iStream = iStr; 
          
            Microsoft.VisualStudio.OLE.Interop.STATSTG[] stInfo = new Microsoft.VisualStudio.OLE.Interop.STATSTG[1];
            iStream.Stat(stInfo, (uint)STATFLAG.STATFLAG_NONAME);

            lSize = Convert.ToInt32(stInfo[0].cbSize.QuadPart);
        }
        
        public override bool CanRead 
        { 
            get { return true; } 
        } 
        
        public override bool CanSeek 
        { 
            get { return false; } 
        } 
        
        public override bool CanWrite 
        { get { return false; } 
        }

        public override long Length
        {
            get { return lSize; }
        }
        
        public override long Position 
        { 
            get { 
                ULARGE_INTEGER[] nlip = new ULARGE_INTEGER[1];
                nlip[0] = new ULARGE_INTEGER();

                LARGE_INTEGER li = new LARGE_INTEGER();
                li.QuadPart = 0;
                iStream.Seek(li, (uint)STREAM_SEEK.STREAM_SEEK_CUR, nlip);
                return Convert.ToInt32(nlip[0]);
            } 
            set {
                LARGE_INTEGER li = new LARGE_INTEGER();
                li.QuadPart = value;
                iStream.Seek(li, (uint)STREAM_SEEK.STREAM_SEEK_SET, null);
            } 
        } 
        
        public override int Read(byte[] buffer, int offset, int count) 
        {
            uint cb = Convert.ToUInt32(count);
            uint uiRead = 0;

            byte[] inBuffer = new byte[count];

            iStream.Read(inBuffer, cb, out uiRead);

            inBuffer.CopyTo(buffer, offset);


            return Convert.ToInt32(uiRead);
        }

        public override void Write(byte[] buffer, int offset, int count)
        {
            throw new NotImplementedException();
        }

        public override void SetLength(long value)
        {
            throw new NotImplementedException();
        }
        public override long Seek(long offset, SeekOrigin origin)
        {
            throw new NotImplementedException();
        }

        public override void Flush()
        {
            throw new NotImplementedException();
        }

    }
}