In this section, we import the modified door FireRating parameter values back into the Revit building model.

The third and last command complements the previous one, reading the updated FireRating parameter values back in from Excel and updating the existing Revit element parameters. Add the following full command to Labs4:

  #region Lab4_3_3_ImportSharedParamFromExcel
  /// <summary>
  /// 4.3.3 Import updated FireRating param values from Excel.
  /// </summary>
  public class Lab4_3_3_ImportSharedParamFromExcel : IExternalCommand
  {
    public IExternalCommand.Result Execute(
      ExternalCommandData commandData,
      ref string message,
      ElementSet elements )
    {
      Application app = commandData.Application;
      Document doc = app.ActiveDocument;

      // Let user select the Excel file
      WinForms.OpenFileDialog dlg = new WinForms.OpenFileDialog();
      dlg.Title = "Select source Excel file from which to update Revit shared parameters";
      dlg.Filter = "Excel spreadsheet files (*.xls;*.xlsx)|*.xls;*.xlsx|All files (*)|*";
      if( WinForms.DialogResult.OK != dlg.ShowDialog() )
      {
        return IExternalCommand.Result.Cancelled;
      }
      //
      // Launch/Get Excel via COM Interop:
      //
      X.Application excel = new X.Application();
      if( null == excel )
      {
        LabUtils.ErrorMsg( "Failed to get or start Excel." );
        return IExternalCommand.Result.Failed;
      }
      excel.Visible = true;
      X.Workbook workbook = excel.Workbooks.Open( dlg.FileName,
        Missing.Value, Missing.Value, Missing.Value,
        Missing.Value, Missing.Value, Missing.Value, Missing.Value,
        Missing.Value, Missing.Value, Missing.Value, Missing.Value,
        Missing.Value, Missing.Value, Missing.Value );
      X.Worksheet worksheet = workbook.ActiveSheet as X.Worksheet;
      //
      // Starting from row 2, loop the rows and extract Id and FireRating param.
      //
      int id;
      double fireRatingValue;
      int row = 2;
      while( true )
      {
        try
        {
          // Extract relevant XLS values
          X.Range r = worksheet.Cells[row, 1] as X.Range;
          if( null == r.Value2 )
          {
            break;
          }
          double d = (double) r.Value2;
          id = (int) d;
          if( 0 >= id )
          {
            break;
          }
          r = worksheet.Cells[row, 4] as X.Range;
          fireRatingValue = (double) r.Value2;
          // Get document's door element via Id
          ElementId elementId;
          elementId.Value = id;
          Element door = doc.get_Element( ref elementId );
          // Set the param
          if( null != door )
          {
            Parameter parameter = door.get_Parameter( LabConstants.gsSharedParamsDefFireRating );
            parameter.Set( fireRatingValue );
          }
        }
        catch( Exception )
        {
          break;
        }
        ++row;
      }
      //
      // Set focus back to Revit (there may be a better way, but this works :-)
      //

#if USE_PROCESS_GET_PROCESSES
      foreach( Process p in Process.GetProcesses() )
      {
        try
        {
          if( "REVIT" == p.ProcessName.ToUpper().Substring( 0, 5 ) )
          {
            // In VB, we can use AppActivate( p.Id );
            // Pre-3.0, I think you may need to use p/invoke and call the native Windows
            // SetForegroundWindow() function directly.
            // http://www.codeproject.com/csharp/windowhider.asp?df=100
            break;
          }
        }
        catch( Exception )
        {
        }
      }
#endif // USE_PROCESS_GET_PROCESSES

      JtRevitWindow w = new JtRevitWindow();
      w.Activate();

      return IExternalCommand.Result.Succeeded;
    }
  }
  #endregion // Lab4_3_3_ImportSharedParamFromExcel

#Region "Lab4_3_3_ImportSharedParamFromExcel"
''' <summary>
''' 4.3.3 Import updated FireRating param values from Excel.
''' </summary>
Public Class Lab4_3_3_ImportSharedParamFromExcel
    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

        ' Let user select the Excel file
        Dim dlgFileXLS As New OpenFileDialog()
        With dlgFileXLS
            .Title = "Select the Excel file to update Revit Shared Parameters from"
            .Filter = "Excel XLS Files (*.xls)|*.xls"
            If Not .ShowDialog() = DialogResult.OK Then
                Return IExternalCommand.Result.Cancelled
            End If
        End With

        ' Launch Excel and open the selected file
        Dim excel As MsExcel.Application = New MsExcel.ApplicationClass()
        If (excel Is Nothing) Then
            MsgBox("Failed to get or start Excel!?")
            Return IExternalCommand.Result.Failed
        End If
        excel.Visible = True
        Dim workbook As MsExcel.Workbook = excel.Workbooks.Open(dlgFileXLS.FileName)
        Dim worksheet As MsExcel.Worksheet = workbook.ActiveSheet

        ' Starting from row 2, loop the rows and extract Id and FireRating param.
        Dim id As Integer
        Dim fireRatingValue As Double
        Dim row As Integer = 2
        Do
            Try
                ' Extract relevant XLS values
                id = worksheet.Cells(row, 1).Value
                If id <= 0 Then Exit Do
                fireRatingValue = worksheet.Cells(row, 4).Value

                ' Get document's door element via Id
                Dim elementId As Autodesk.Revit.ElementId
                elementId.Value = id
                Dim door As Autodesk.Revit.Element = app.ActiveDocument.Element(elementId)

                ' Set the param
                If Not (door Is Nothing) Then
                    Dim parameter As Parameter = door.Parameter(gsSharedParamsDefFireRating)
                    parameter.Set(fireRatingValue)
                End If

            Catch
                Exit Do
            End Try

            row = row + 1
        Loop

        ' Set focus back to Revit (there may be a better way, but this works :-)
        Dim p, cPs() As Process
        cPs = Process.GetProcesses()
        For Each p In cPs
            Try
                If p.ProcessName.ToUpper.Substring(0, 5) = "REVIT" Then
                    AppActivate(p.Id)
                    Exit For
                End If
            Catch
            End Try
        Next

        Return IExternalCommand.Result.Succeeded
    End Function
End Class

#End Region

Compile the code and update Revit.ini again. Before running this command, make sure you first export some Revit door elements to the Excel sheet using the previous command, update some of the FireRating values in Excel and save the file, remembering the path which you will need to select it to read it in again.