© 2010 Autodesk
Introduction to Revit 2011 API
Element Filtering
2.2 List of Instances of a Specific Object Class - Component Family
§Collect all the instances of door
<VB.NET>
    Dim doorCollector = New FilteredElementCollector(m_rvtDoc). _
        OfClass(GetType(FamilyInstance))
    doorCollector.OfCategory(BuiltInCategory.OST_Doors)
    Dim doorList As IList(Of Element) = doorCollector.ToElements
</VB.NET>