问如何在revit-api c#中从revit文档中向revit族元素添加参数

EN

 foreach (var item in MainModel.listElement)//List<Element>
 {
    FamilyInstance elFamInst = item as FamilyInstance;
    if (elFamInst.Symbol.FamilyName == "MainFamilyName")//Bend Family
    {
       ElementId id = item.GetTypeId();
       ElementType et = doc.GetElement(id) as ElementType;

       Family fam = elFamInst.Symbol.Family;

       if (elFamInst.SuperComponent == null)
       {
          var subElements = elFamInst.GetSubComponentIds();
          if (subElements.Count != 0)
          {
             foreach (var aSubElemId in subElements)
             {
                var aSubElem = doc.GetElement(aSubElemId);
                if (aSubElem is FamilyInstance)
                {
                   FamilyInstance subEl = aSubElem as FamilyInstance;
                   Family fm = subEl.Symbol.Family;
                   if(subEl.Symbol.FamilyName == "subFamilyName")//coupling family
                   {
                       Document docfamily = doc.EditFamily(fam);
                       if (null != docfamily && docfamily.IsFamilyDocument == true)
                       {
                          FamilyManager familyManager = docfamily.FamilyManager;
                          using (Transaction trans = new Transaction(docfamily, "param"))
                          {
                              trans.Start();
                              FamilyParameter fp = familyManager.AddParameter("Namess",BuiltInParameterGroup.PG_IDENTITY_DATA,ParameterType.Text, false);
                              familyManager.Set(fp, "JP");
                              trans.Commit();
                          }
                        }

                    }

                  }
               }
             }
          }
       }
    }