The StreamConnector class comes with ADE in the examples folder. It wraps the IStream class used by COM, allowing convenient use of CAObject::PictureToStream and CATable::GraphToStream from a .NET program.
' StreamConnector.vb
'
' (c) 2003-2015 Lumina Decision Systems, Inc.   All rights reserved.
'
' The System.IO.Stream class in .NET is not compatible with the IStream
' class used by COM.  This class adds a wrapper around an existing IO.Stream
' to implement the IStream interface.  The resulting class is both an
' IStream and a Stream.  The underlying stream does not have to be 
' inheritable.
 
 
Imports System.Collections.Generic
Imports System.Runtime.InteropServices
Imports System.Runtime.InteropServices.ComTypes
Imports System.IO
 
Public Class StreamConnector
   Inherits Stream
   Implements IStream
 
   Sub New(ByVal stream As Stream)
       m_stream = stream
   End Sub
 
   ' ==========================================================================================
   ' First we replicate the System.IO.Stream interface:
   Public Overrides Sub Close()
       m_stream.Close()
   End Sub
   Public Overloads Sub Dispose()
       m_stream.Dispose()
   End Sub
   'Protected Overrides Sub Dispose(ByVal disposing As Boolean)
   '    m_stream.Dispose(disposing)
   'End Sub
   Public Overrides Sub EndWrite(ByVal asyncResult As System.IAsyncResult)
       m_stream.EndWrite(asyncResult)
   End Sub
   Public Overrides Sub Flush()
       m_stream.Flush()
   End Sub
   Public Overrides Sub SetLength(ByVal value As Long)
       m_stream.SetLength(value)
   End Sub
   Public Overrides Sub Write(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer)
       m_stream.Write(buffer, offset, count)
   End Sub
   Public Overrides Sub WriteByte(ByVal value As Byte)
       m_stream.WriteByte(value)
   End Sub
   Public Overrides Function BeginRead(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer, ByVal callback As System.AsyncCallback,  ByVal state As Object) As System.IAsyncResult
       BeginRead = m_stream.BeginRead(buffer, offset, count, callback, state)
   End Function
   Public Overrides Function BeginWrite(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer, ByVal callback As System.AsyncCallback, ByVal state As Object) As System.IAsyncResult
       BeginWrite = m_stream.BeginWrite(buffer, offset, count, callback, state)
   End Function
   Public Overrides Function EndRead(ByVal asyncResult As System.IAsyncResult) As Integer
       EndRead = m_stream.EndRead(asyncResult)
   End Function
   Public Overrides Function Read(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer) As Integer
       Read = m_stream.Read(buffer, offset, count)
   End Function
   Public Overrides Function ReadByte() As Integer
       ReadByte = m_stream.ReadByte()
   End Function
   Public Overrides Function Seek(ByVal offset As Long, ByVal origin As System.IO.SeekOrigin) As Long
       Seek = m_stream.Seek(offset, origin)
   End Function
   Public Overrides ReadOnly Property CanRead() As Boolean
       Get
           CanRead = m_stream.CanRead
       End Get
   End Property
   Public Overrides ReadOnly Property CanSeek() As Boolean
       Get
           CanSeek = m_stream.CanSeek
       End Get
   End Property
   Public Overrides ReadOnly Property CanTimeout() As Boolean
       Get
           CanTimeout = m_stream.CanTimeout
       End Get
   End Property
   Public Overrides ReadOnly Property CanWrite() As Boolean
       Get
           CanWrite = m_stream.CanWrite
       End Get
   End Property
   Public Overrides ReadOnly Property Length() As Long
       Get
           Length = m_stream.Length
       End Get
   End Property
   Public Overrides Property Position() As Long
       Get
           Position = m_stream.Position
       End Get
       Set(ByVal value As Long)
           m_stream.Position = value
       End Set
   End Property
   Public Overrides Property ReadTimeout() As Integer
       Get
           ReadTimeout = m_stream.ReadTimeout
       End Get
       Set(ByVal value As Integer)
           m_stream.ReadTimeout = value
       End Set
   End Property
   Public Overrides Property WriteTimeout() As Integer
       Get
           WriteTimeout = m_stream.WriteTimeout
       End Get
       Set(ByVal value As Integer)
           m_stream.WriteTimeout = value
       End Set
   End Property
 
   ' ==========================================================================================
   ' And implement the IStream interface:
 
   Sub Clone(ByRef ppstm As IStream) Implements IStream.Clone
       ppstm = New StreamConnector(m_stream)
   End Sub
 
   Sub Commit(ByVal flags As Integer) Implements IStream.Commit
   End Sub
 
   Overloads Sub CopyTo(ByVal dst As IStream, ByVal cb As Long, ByVal pcbRead As System.IntPtr, ByVal pcbWritten As System.IntPtr) Implements IStream.CopyTo
       Dim bytes(cb) As Byte
       Dim n As Integer = m_stream.Read(bytes, 0, cb)
       System.Runtime.InteropServices.Marshal.WriteInt32(pcbWritten, n)
       dst.Write(bytes, n, pcbWritten)
   End Sub
 
   Sub LockRegion(ByVal libOffset As Long, ByVal cb As Long, ByVal dwLockType As Integer) Implements IStream.LockRegion
   End Sub
 
   Sub IStreamRead(ByVal pv() As Byte, ByVal cb As Integer, ByVal pcbRead As System.IntPtr) Implements IStream.Read
       Marshal.WriteInt32(pcbRead, m_stream.Read(pv, 0, cb))
   End Sub
 
   Sub Revert() Implements IStream.Revert
   End Sub
   Sub IStreamSeek(ByVal dlibMove As Long, ByVal dwOrigin As Integer, ByVal plibNewPosition As System.IntPtr) Implements IStream.Seek
       Dim so As SeekOrigin = SeekOrigin.Begin
       Select Case dwOrigin
           Case 1
               so = SeekOrigin.Current
           Case 2
               so = SeekOrigin.End
       End Select
       Marshal.WriteInt32(plibNewPosition, m_stream.Seek(dlibMove, so))
   End Sub
   Sub SetSize(ByVal libNewSize As Long) Implements IStream.SetSize
       m_stream.SetLength(libNewSize)
   End Sub
   Sub Stat(ByRef pstatstg As System.Runtime.InteropServices.ComTypes.STATSTG, ByVal grfStatFlag As Integer) Implements IStream.Stat
       pstatstg = New ComTypes.STATSTG
   End Sub
   Sub UnlockRegion(ByVal libOffset As Long, ByVal cb As Long, ByVal dwLockType As Integer) Implements IStream.UnlockRegion
   End Sub
   Sub IStreamWrite(ByVal pv() As Byte, ByVal cb As Integer, ByVal pcbWritten As System.IntPtr) Implements IStream.Write
       If cb < pv.Length Then cb = pv.Length
       m_stream.Write(pv, 0, cb)
       Marshal.WriteInt32(pcbWritten, cb)
   End Sub
 
   Private m_stream As Stream
End Class
StreamConnector

See Also
