Revit API遍历系统族布置喷头

系统族可以通过内参遍历，遍历出来是个FamilySymbol
喷头属于系统族，但不能通过NewDuct();类似这样的方法布置。
必须使用

NewFamilyInstance()

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using WinForm = System.Windows.Forms;

using Autodesk.Revit.UI;
using Autodesk.Revit.DB;
using Autodesk.Revit.Attributes;

using Autodesk.Revit.DB.Mechanical;
using Autodesk.Revit.UI.Selection;
using Autodesk.Revit.ApplicationServices;

using Autodesk.Revit.DB.Structure;
using Autodesk.Revit.DB.ExtensibleStorage;
using Autodesk.Revit.DB.Plumbing;
using Autodesk.Revit.DB.Architecture;

using System.Xml;

namespace RevitCodes
{

    [TransactionAttribute(Autodesk.Revit.Attributes.TransactionMode.Manual)]
    public class cmdSprinklers : IExternalCommand
    {
        public Result Execute(ExternalCommandData commandData, ref string messages, ElementSet elements)
        {
            UIApplication uiApp = commandData.Application;
            Document doc = uiApp.ActiveUIDocument.Document;
            Selection sel = uiApp.ActiveUIDocument.Selection;

            Transaction ts = new Transaction(doc, "http://revit.5d6d.com");
            ts.Start();

            //从系统族中过滤出喷头，是作为一个FamilySymbol存在的
            FilteredElementCollector collector = new FilteredElementCollector(doc);
            //此法可以只过滤系统类型
            //collector.OfClass(typeof(FamilySymbol)).OfCategory(BuiltInCategory.OST_Sprinklers);
            collector.OfCategory(BuiltInCategory.OST_Sprinklers);
            FamilyInstance fi = null;//如果已经布置了，就是族实例
            int iFi = ;
            FamilySymbol symbol = null;//系统族是族符号
            int iFs = ;
            foreach (Element el in collector.ToElements())
            {
                fi = el as FamilyInstance;
                if (fi != null)
                    iFi += ;
                symbol = el as FamilySymbol;
                if (symbol != null)
                    iFs += ;
            }
            TaskDialog.Show("count", iFi + "," + iFs);
            if (fi != null)
                doc.Create.NewFamilyInstance(new XYZ(, , ), fi.Symbol, StructuralType.Beam);
            if (symbol != null)
                doc.Create.NewFamilyInstance(new XYZ(, , ), symbol, StructuralType.Beam);

            ts.Commit();

            return Result.Succeeded;
        }
        XYZ PointOnFace(PlanarFace face)
        {
            XYZ p = new XYZ(, , );
            Mesh mesh = face.Triangulate();

            for (int i = ; i < mesh.NumTriangles; ++i)
            {
                MeshTriangle triangle = mesh.get_Triangle(i);
                p += triangle.get_Vertex();
                p += triangle.get_Vertex();
                p += triangle.get_Vertex();
                p *= 0.3333333333333333;
                break;
            }
            return p;
        }
    }
}

url:http://greatverve.cnblogs.com/p/api-Sprinklers.html