Revit二次开发之“选择某一楼层的墙”

其实就是过滤器的用法。这里想要找到同一楼层中的风管，不可行。
要用：duct.ReferenceLevel

//选择某一楼层上的墙
[Transaction(TransactionMode.Manual)]
[Regeneration(RegenerationOption.Manual)]
//[Journaling(JournalingMode.NoCommandData)]
public class SelectFloorObj : IExternalCommand
{
    public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
    {
        UIDocument uiDoc = commandData.Application.ActiveUIDocument;
        Selection selection = uiDoc.Selection;

        //把标高1上的墙加入选择集
        FilteredElementCollector collector = new FilteredElementCollector(uiDoc.Document);
        collector.OfClass(typeof(Wall)).OfCategory(BuiltInCategory.OST_Walls);
        IList<Element> lists = collector.ToElements();

        foreach (Element el in lists)
        {
            if (el.Level.Name == "标高 1")
                selection.Elements.Add(el);//添加到选择集
        }

        //风管的Level属性为空，不能这样做。
        //FilteredElementCollector collector = new FilteredElementCollector(uiDoc.Document);
        //collector.OfClass(typeof(Duct)).OfCategory(BuiltInCategory.OST_DuctCurves);
        //IList<Element> lists = collector.ToElements();

        //foreach (Element el in lists)
        //{
        //    Duct duct = el as Duct;
        //    MessageBox.Show(duct.LevelOffset.ToString());
        //    if (duct.Level != null)
        //    {
        //        if (duct.Level.Name == "标高 1")
        //        {
        //            selection.Elements.Add(duct);
        //        }
        //    }
        //}

        return Result.Succeeded;
    }
}

from:http://revit.5d6d.com/thread-1076-1-3.html