The following sample enumerates the arguments of an OLE event when OLEEvent is fired.

Private Sub Pivot1_OleEvent(ByVal Ev As EXPIVOTLibCtl.IOleEvent)
   Debug.Print "Event name:" & Ev.Name
   If (Ev.CountParam = 0) Then
      Debug.Print "The event has no arguments."
   Else
      Debug.Print "The event has the following arguments:"
      Dim i As Long
      For i = 0 To Ev.CountParam - 1
         Debug.Print Ev(i).Name; " = " & Ev(i).Value
      Next
   End If
End Sub

The C++ example below captures and displays the events triggered by an ActiveX control while it is hosted:

 #import <expivot.dll>

static CString V2S( VARIANT* pv, LPCTSTR szDefault = _T("") )
{
	if ( pv )
	{
		if ( pv->vt == VT_ERROR )
			return szDefault;

		COleVariant vt;
		vt.ChangeType( VT_BSTR, pv );
		return V_BSTR( &vt );
	}
	return szDefault;
}

void OnOleEventPivot1( LPDISPATCH Ev) 
{
	EXPIVOTLib::IOleEventPtr spEvent( Ev );
	CString strOutput;
	strOutput.Format( "Event's name: %s\n", spEvent->Name.operator const char *() );
	OutputDebugString( strOutput ); 
	if ( spEvent->CountParam == 0 )
		OutputDebugString( "The event has no parameters." ); 
	else
	{
		for ( long i = 0; i < spEvent->CountParam; i++ )
		{
			EXPIVOTLib::IOleEventParamPtr spParam = spEvent->GetParam( COleVariant( i ) );
			strOutput.Format( "Name: %s, Value: %s\n", spParam->Name.operator const char *(), V2S( &spParam->Value ) );
			OutputDebugString( strOutput ); 
		}
	}
	OutputDebugString( "" ); 
}

The #import clause is required to get the wrapper classes for IOleEvent and IOleEventParam objects, that are not defined by the MFC class wizard. The same #import statement defines the EXPIVOTLib namespace that include all objects and types of the control's TypeLibrary. In case your expivot.dll library is located to another place than the system folder or well known path, the path to the library should be provided, in order to let the VC finds the type library.  

The VB.NET example below captures and displays the events triggered by an ActiveX control while it is hosted:

Private Sub AxPivot1_OleEvent(ByVal sender As Object, ByVal e As AxEXPIVOTLib._IPivotEvents_OleEventEvent) Handles AxPivot1.OleEvent
    Debug.WriteLine("Event's name: " & e.ev.Name)
    Dim i As Long
    For i = 0 To e.ev.CountParam - 1
        Dim eP As EXPIVOTLib.OleEventParam
        eP = e.ev(i)
        Debug.WriteLine("Name: " & e.ev.Name & " Value: " & eP.Value)
    Next
End Sub

The C# example below captures and displays the events triggered by an ActiveX control while it is hosted:

private void axPivot1_OleEvent(object sender, AxEXPIVOTLib._IPivotEvents_OleEventEvent e)
{
	System.Diagnostics.Debug.WriteLine( "Event's name: " + e.ev.Name.ToString() );
	for ( int i= 0; i < e.ev.CountParam ; i++ )
	{
		EXPIVOTLib.IOleEventParam evP = e.ev[i];
		System.Diagnostics.Debug.WriteLine( "Name: " + evP.Name.ToString() + ", Value: " + evP.Value.ToString() );
	}
}

The VFP example below captures and displays the events triggered by an ActiveX control while it is hosted:

*** ActiveX Control Event ***
LPARAMETERS  ev

local s
s = "Event's name: " + ev.Name
for i = 0 to ev.CountParam - 1
		s = s +  "Name: " + ev.Param(i).Name + " ,Value: " + Str(ev.Param(i).Value)
endfor
wait window nowait s