See example/usage below for istream implementation and wrapper. Attachment has two c# files includes MamagedIStream and IStreamWrapper class.

Usage IStreamWrapper and ManagedIStream:

            
            //IStreamWrapper  usage
            IStream iStream = null; // set a new instance
            IStreamWrapper sw = new IStreamWrapper(iStream);
            byte[] data = new byte[1];
            sw.Read(data, 0, 1);


            //ManagedIStream usage
            Stream ms = null; // set a new stream instance
            ManagedIStream managedIStream = new ManagedIStream(ms); // ManagedIStream class implements IStream interface.

Download Files:
CSharpExamples-Managed IStream and IStreamWrapper.RAR