In this section, we will extract some elementary information from the room objects in a Revit model and also list their boundaries. To display the information associated with each room, we can iterate through all the Room type elements in the model and display the parameters associated with each.

Using the new filtering mechanism in Revit 2009, we can select all elements of 'Room' type only. Once we have the set of Room elements, use the get_Parameter method in C# and Parameter in VB.Net on each Room element to extract information like the Name and Number associated with it.

  /// <summary>
  /// List room boundaries.
  /// </summary>
  public class Lab5_3_Rooms : IExternalCommand
  {
    public IExternalCommand.Result Execute(
      ExternalCommandData commandData,
      ref string message,
      ElementSet elements )
    {
      Application app = commandData.Application;

      // List all Room Elements
      List<RvtElement> rooms = LabUtils.GetAllRooms(app);
      if( 0 == rooms.Count )
      {
        LabUtils.InfoMsg( "There are no rooms in this model!" );
      }
      else
      {
        foreach( Room room in rooms )
        {
          // Some identification parameters
          // (there are probably built-in Params for this, but this works :-)

          Parameter p = room.get_Parameter( "Name" );
          string roomName = null == p ? "?" : p.AsString();

          p = room.get_Parameter( "Number" );
          string roomNumber = null == p ? "?" : p.AsString();

          string sMsg = "Room Id=" + room.Id.Value.ToString()
            + " Name=" + roomName + " Number=" + roomNumber + "\r\n";

          LabUtils.InfoMsg( sMsg );
        }
      }
    return IExternalCommand.Result.Succeeded;
    }
  }

    ''' 

    ''' List room boundaries.
    ''' 
    Public Class Lab5_3_Rooms
        Implements IExternalCommand
        Public Function Execute( _
            ByVal commandData As ExternalCommandData, _
            ByRef message As String, _
            ByVal elements As ElementSet) _
        As IExternalCommand.Result Implements IExternalCommand.Execute

            Dim app As Revit.Application = commandData.Application
            Dim rm As Room

            ' List all Room Elements
            Dim rooms As List(Of Element) = LabUtils.GetAllRooms(app)
            If (0 = rooms.Count) Then
                MsgBox("There are no rooms in this model!")
            Else
                For Each rm In rooms

                    ' Some identification Parameters
                    ' (there are probably built-in Params for this, but this works :-)

                    Dim roomName As String = "?"
                    Dim p As Parameter = rm.Parameter("Name")
                    If Not p Is Nothing Then
                        roomName = p.AsString
                    End If

                    Dim roomNumber As String = "?"
                    p = rm.Parameter("Number")
                    If Not p Is Nothing Then
                        roomNumber = p.AsString
                    End If

                    Dim sMsg As String = "Room Id=" & rm.Id.Value.ToString & " Name=" & roomName & " Number=" & roomNumber & vbCrLf
                    MsgBox(sMsg)
                Next
            End If
            Return IExternalCommand.Result.Succeeded
        End Function
    End Class

Extracting the Room boundary is a bit more complex.

The room boundary property is of BoundarySegmentArrayArray type which is an array of BoundarySegmentArray objects. Each BoundarySegmentArray makes up a circuit or a continuous line in which one segment joins next. BoundarySegmentArray comprises of BoundarySegment objects which make up the region and can be of line or arc type. Room boundary will return null if the room is not in an enclosed region or only exists in the schedule. Using each of the room objects obtained in the previous section in this lab, we can extract the boundary property as follows:

    // Loop all boundaries of this room
    BoundarySegmentArrayArray boundaries = room.Boundary;
    // Check to ensure room has boundary
    if (null != boundaries)
    {
      int iB = 0;
      foreach (BoundarySegmentArray boundary in boundaries)
      {
        ++iB;
        sMsg += "\r\n    Boundary " + iB + ":";
        int iSeg = 0;
        foreach (BoundarySegment segment in boundary)
        {
          ++iSeg;

          // Segment's curve
          Curve crv = segment.Curve;
          if (crv is Line) // LINE
          {
            Line line = crv as Line;
            XYZ ptS = line.get_EndPoint(0);
            XYZ ptE = line.get_EndPoint(1);
            sMsg += "\r\n        Segment " + iSeg + " is a LINE: "
              + LabUtils.PointString(ptS) + " ; "
              + LabUtils.PointString(ptE);
          }
          else if (crv is Arc) // ARC
          {
            Arc arc = crv as Arc;
            XYZ ptS = arc.get_EndPoint(0);
            XYZ ptE = arc.get_EndPoint(1);
            double r = arc.Radius;
            sMsg += "\r\n        Segment " + iSeg + " is an ARC:"
              + LabUtils.PointString(ptS) + " ; "
              + LabUtils.PointString(ptE) + " ; R=" + r;
          }
        }
      }
    }

    ' Loop all Boundaries of this Room
    Dim boundaries As Rooms.BoundarySegmentArrayArray = rm.Boundary
    ' Check to ensure the room has boundary
    If Not (boundaries Is Nothing) Then

        Dim iB As Integer = 0
        Dim boundary As Rooms.BoundarySegmentArray
        For Each boundary In boundaries

            ' Msg
            iB += 1
            sMsg += vbCrLf & "    Boundary " & iB & ":"

            ' Loop through all Segments of that Boundary
            Dim iSeg As Integer = 0
            Dim segment As Rooms.BoundarySegment
            For Each segment In boundary
                iSeg += 1

                ' Segment's curve
                Dim crv As Geometry.Curve = segment.Curve

                If TypeOf crv Is Geometry.Line Then                     'LINE

                    Dim line As Geometry.Line = crv
                    Dim ptS As Geometry.XYZ = line.EndPoint(0)
                    Dim ptE As Geometry.XYZ = line.EndPoint(1)

                    sMsg += vbCrLf & "        Segment " & iSeg & " is a LINE:" & _
                       ptS.X & ", " & ptS.Y & ", " & ptS.Z & " ; " & _
                       ptE.X & ", " & ptE.Y & ", " & ptE.Z

                ElseIf TypeOf crv Is Geometry.Arc Then                      'ARC

                    Dim arc As Arc = crv
                    Dim ptS As Geometry.XYZ = arc.EndPoint(0)
                    Dim ptE As Geometry.XYZ = arc.EndPoint(1)
                    Dim r As Double = arc.Radius

                    sMsg += vbCrLf & "        Segment " & iSeg & " is an ARC:" & _
                       ptS.X & ", " & ptS.Y & ", " & ptS.Z & " ; " & _
                       ptE.X & ", " & ptE.Y & ", " & ptE.Z & " ; R=" & r

                End If
            Next
        Next
    End If

Build the project, adjust the ini file and examine the output in a model with a few room instances with different types of boundary segments.