Revit二次开发之“框选”过滤

这里的框选，必须是整体选中。
框选的方式分两种：
左上->右下，必须整体选中。
右下->左上，只要部分选中。

public void SelectPlanarFaces(Autodesk.Revit.DB.Document document)
{
    UIDocument uidoc = new UIDocument(document);
    ISelectionFilter selFilter = new PlanarFacesSelectionFilter(document);
    IList<Reference> faces = uidoc.Selection.PickObjects(ObjectType.Face, selFilter, "Select multiple planar faces");
}

public class PlanarFacesSelectionFilter : ISelectionFilter
{
    Document doc = null;
    public PlanarFacesSelectionFilter(Document document)
    {
        doc = document;
    }

    public bool AllowElement(Element element)
    {
        return true;
    }

    public bool AllowReference(Reference refer, XYZ point)
    {   
        if (doc.GetElement(refer).GetGeometryObjectFromReference(refer) is PlanarFace)
        {
            return true; // Only return true for planar faces. Non-planar faces will not be selectable
        }
        return false;
    }
}

url:http://revit.5d6d.com/thread-873-1-4.html