Revit二次开发，删除载入的族

    　　　　　　　 Document doc = commandData.Application.ActiveUIDocument.Document;
            　　 Family family = null;
               
                string s = "c:/xxx.rfa";

                Transaction tran = new Transaction(doc,"载入族");
                tran.Start();
                bool b = doc.LoadFamily(s, out family);
                tran.Commit();

                if (b)
                {           
                    Element element = family as Element;           
                    ElementFilter sanshuiCategoryFilter = new ElementCategoryFilter(family.FamilyCategoryId);
                    ElementFilter familySymbolFilter = new ElementClassFilter(typeof(FamilySymbol));
                    LogicalAndFilter andFilter = new LogicalAndFilter(sanshuiCategoryFilter, familySymbolFilter);
                    FilteredElementCollector sanshuiSymbols = new FilteredElementCollector(doc);
                    sanshuiSymbols = sanshuiSymbols.WherePasses(andFilter);
                    FamilySymbol symbol = null;
                    foreach (FamilySymbol f in sanshuiSymbols)
                    {                       
                         symbol = f;
                         break；
                    }
                    using (Transaction tran1 = new Transaction(doc, "删除载入族"))
                    {
                        tran1.Start();
                        doc.Delete(symbol.Family.Id);
                        tran1.Commit();
                    }
                }
            

在Revit二次开发里，当我载入族后，如何用代码删除，这个问题我研究了2天，幸得高人指点方才突破，感谢她@若爱，请深爱