NNTP EnvelopeFields Code Example

The following code example can be used only with event sinks. The IMessage.EnvelopeFields property returns an empty collection in all cases except for a Message object reference passed to a sink during a transport event. This example loops through the envelope fields and writes each name-value pair to a log file called Fields.log.

Example

[Visual Basic]

Implements INNTPOnPost

Sub INNTPOnPost_OnPost(ByVal iMsg as CDO.Message, EventStatus as CdoEventStatus)
  Dim Fld as ADODB.Field
  Dim strOutPut as String
  For Each Fld In iMsg.EnvelopeFields
     strOutPut = strOutPut & Fld .Name & ": " & Fld .Value & vbCrLf
  Next
  Dim FS as New Scripting.FileSystemObject
  Dim File as Scripting.TextStream
  Set File = FS.CreateTextFile("c:\envelopefieldlog\fields.log",True,False)
  File.Write strOutPut
End Sub

[C++,IDL]

#include <atlbase.h>
#include <atlimpl.cpp>
#import  <msado15.dll> no_namespace raw_interfaces_only
#import  <cdosys.dll>  no_namespace raw_interfaces_only
#import  <seo.dll>     no_namespace raw_interfaces_only

/////////////////////////////////////////////////////////////////////////////
// CSink1
class ATL_NO_VTABLE CSink1 : 
public CComObjectRootEx<CComSingleThreadModel>,
public CComCoClass<CSink1, &CLSID_Sink1>,
public IDispatchImpl<INNTPOnPost, &__uuidof(INNTPOnPost), &LIBID_TRANSSINKEXLib>
{
public:
CSink1()
{
}

DECLARE_REGISTRY_RESOURCEID(IDR_SINK1)

DECLARE_PROTECT_FINAL_CONSTRUCT()

BEGIN_COM_MAP(CSink1)
  COM_INTERFACE_ENTRY(INNTPOnPost)
  COM_INTERFACE_ENTRY(IEventIsCacheable)
  COM_INTERFACE_ENTRY(IDispatch)
END_COM_MAP()

// ISink1
public:
STDMETHOD(IsCacheable)() { return S_OK;}
STDMETHOD(OnPost)(IMessage* pMsg, CdoEventStatus* pStat);

};

STDMETHODIMP MyClass::OnPost([in] IMessage *Msg, [in,out] CdoEventStatus *EventStatus)
{
    // This example for the most part ignores
   // error values.  This is not good practice
   // in general!

  HRESULT hr = S_OK;
  CComPtr<Field>  pField;
  CComPtr<Fields> pFields;
  Msg->get_EnvelopeFields(&pFields);
  CComBSTR    bstrName;
  CComVariant varValue;
  CComBSTR    bstrOut = "";
  long count = 0;
  pFields->get_Count(&count);

  for(long i = 0;i<count;i++) {   
    pFields->get_Item(CComVariant((long)i), &pField);
    if(SUCCEEDED(hr)){
      pField->get_Name(&bstrName);
      pField->get_Value(&varValue);

      bstrOut += bstrName;
      bstrOut += ":";
      bstrOut += varValue.bstrVal;
      bstrOut += "\r\n";

      bstrName.Empty();
      varValue.Clear();
      pField.Release();
    }
  }

    LPCWSTR szFilename = L"c:\\logs\\nntpevents.txt";
    HANDLE hFile;
    int nBufSize = 0;
    ULONG nSizeWritten = 0 ;
    BOOL fRC = FALSE;

    hFile = CreateFileW(szFilename,
                       GENERIC_WRITE,
                       FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
                       NULL,
                       OPEN_ALWAYS,
                       FILE_ATTRIBUTE_NORMAL,
                       NULL);
    if(hFile == INVALID_HANDLE_VALUE)
        return E_POINTER;

  SetFilePointer(hFile,0,NULL,FILE_END);
  nBufSize = lstrlenW(bstrOutPut);
    fRC = WriteFile(hFile,bstrOutPut,nBufSize * 2,&nSizeWritten,NULL);
    if(fRC == FALSE)
        return S_FALSE;
    CloseHandle(hFile);

  pFields.Release();
  Msg->Release();
  return hr;
}