Loading Message from within ADO Stream Objects

To load a serialized message into a Microsoft Collaboration Data Objects (CDO) Message object from within a Microsoft® ActiveX® Data Object (ADO) Stream object, perform the following steps:

1. Retrieve the IDataSource interface on the Message object.
2. Create or otherwise obtain a _Stream object reference on an ADO Stream object.
3. Using the IDataSource interface on the Message object, call the OpenObject method, passing the _Stream object reference as the first argument, and the string "_Stream" as the second.

' Reference to Microsoft ActiveX Data Objects 2.5 Library
' Reference to Microsoft CDO for Windows 2000 Library
Function LoadMessageFromFile(Path As String) As Message
    Dim Stm As New Stream
    Stm.Open
    Stm.LoadFromFile Path
    Dim iMsg As New CDO.Message
    Dim iDsrc As IDataSource
    Set iDsrc = iMsg
    iDsrc.OpenObject Stm, "_Stream"
    Set LoadMessageFromFile = iMsg
End Function

#import "c:\program files\common files\system\ado\msado15.dll" no_namespace
#import <cdosys.dll> no_namespace
// ...
IMessagePtr Load_Message_from_File(_bstr_t path)
{
      /*
      ** This example shows a common use of the ADO Stream
      ** object with CDO, namely, opening a serialized
      ** message from a file on disk and loading it into
      ** a CDO Message object.
      **/

      _StreamPtr  pStm(__uuidof(Stream));
      _variant_t varOptional(DISP_E_PARAMNOTFOUND,VT_ERROR);
      try {
            pStm->raw_Open(varOptional, adModeUnknown, adOpenStreamUnspecified,NULL,NULL);
            pStm->LoadFromFile(path);
      }
      catch(_com_error e)
      {
            throw e;
      }

      IMessagePtr iMsg(__uuidof(Message));
      IDataSourcePtr iDsrc;
      iDsrc = iMsg;

      try {
            iDsrc->OpenObject(pStm,_bstr_t("_Stream"));
      }
      catch(_com_error e)
      {
            throw e;
      }


      // ....

      return iMsg;
}
Function LoadMessageFromFile(Path)
    Dim Stm
    Set Stm = CreateObject("ADODB.Stream")
    Stm.Open
    Stm.LoadFromFile Path
    Dim iMsg
    Set iMsg = CreateObject("CDO.Message")
    Dim iDsrc
    Set iDsrc = iMsg.DataSource
    iDsrc.OpenObject Stm, "_Stream"
    Set LoadMessageFromFile = iMsg
End Function

SaveToObject Method
OpenObject Method
IDataSource Interface