Comment mettre à jour des données d'un document père à partir d'un document fils dans une action auto de Workflow

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Avanteam.Workflow.Runtime;
using Avanteam.Workflow.ComponentModel;
using Avanteam.Workflow.ComponentModel.Shared;
using Avanteam.Workflow.ComponentModel.Runtime;
using Avanteam.Application;
using Avanteam.Application.DataSource;
using Avanteam.Documents;
using Avanteam.Documents.DataSource;

namespace Avanteam.Kernel.Scripting
{
    public class CSCode
    {
        public bool Execute(Hashtable parameters)
        {
            ApplicationDataSource dataSource = parameters["ApplicationDataSource"] as ApplicationDataSource;

            Instance instance = parameters["Instance"] as Instance;
            DocumentDocHelper DocSource = dataSource.Document;     //Initialisation du doc fils           
            string IdPreviousVersion = DocSource.GetStringValue("IdPreviousVersion");
            if (!String.IsNullOrEmpty(IdPreviousVersion))
            {
                DocumentDocHelper DocPrevious = dataSource.DocumentsDataSource.GetDocument(IdPreviousVersion); //Initialisation du doc Père
                DocPrevious.SetValues("QVersionDoing", "0");
                DocPrevious.SaveDocument();
            }
            return true;
        }
    }
}