In this section, we export the door element ids and FireRating parameter values to Excel.

Before adding the command, we implement another reusable utility to get the gloally unique identifier or GUID for a given shared parameter group and name. We will need this later for the GUID argument of the Revit.Element.Parameter() method. Add the following method to LabUtils:

    /// <summary>
    /// Get GUID for a given shared param name.
    /// </summary>
    /// <param name="app">Revit application</param>
    /// <param name="defGroup">Definition group name</param>
    /// <param name="defName">Definition name</param>
    /// <returns>GUID</returns>
    public static Guid SharedParamGUID( Application app, string defGroup, string defName )
    {
      Guid guid = Guid.Empty;
      try
      {
        Autodesk.Revit.Parameters.DefinitionFile file = app.OpenSharedParameterFile();
        Autodesk.Revit.Parameters.DefinitionGroup group = file.Groups.get_Item( defGroup );
        Autodesk.Revit.Parameters.Definition definition = group.Definitions.get_Item( defName );
        Autodesk.Revit.Parameters.ExternalDefinition externalDefinition = definition as ExternalDefinition;
        guid = externalDefinition.GUID;
      }
      catch( Exception )
      {
      }
      return guid;
    }
    #endregion // Helpers for shared parameters

    ''' <summary>
    ''' Get GUID for a given shared param name.
    ''' </summary>
        Shared Function SharedParamGUID(ByVal app As Revit.Application, _
                                        ByVal defGroup As String, _
                                        ByVal defName As String) As Guid

        Dim guid As Guid = guid.Empty

        Try
            Dim file As Autodesk.Revit.Parameters.DefinitionFile = app.OpenSharedParameterFile
            Dim group As Autodesk.Revit.Parameters.DefinitionGroup = file.Groups.Item(defGroup)
            Dim definition As Autodesk.Revit.Parameters.Definition = group.Definitions.Item(defName)
            Dim externalDefinition As Autodesk.Revit.Parameters.ExternalDefinition = definition
            guid = externalDefinition.GUID
        Catch
        End Try

        Return guid

    End Function

Add the following full command class to Labs4. We first launch or get Excel and then loop and export all doors row by row. Note how we use the GUID to get the parameter and that we also export the doors' standard tag (mark) and level parameters.

  #region Lab4_3_2_ExportSharedParamToExcel
  /// <summary>
  /// 4.3.2 Export all door ids and FireRating param values to Excel.
  /// </summary>
  public class Lab4_3_2_ExportSharedParamToExcel : IExternalCommand
  {
    public IExternalCommand.Result Execute(
      ExternalCommandData commandData,
      ref string message,
      ElementSet elements )
    {
      Application app = commandData.Application;
      Document doc = app.ActiveDocument;
      Category cat = doc.Settings.Categories.get_Item( Lab4_3_1_CreateAndBindSharedParam.Bic );
      // Launch Excel (same as in Lab 4_2, so we really should have better created some utils...)
      X.Application excel = new X.ApplicationClass();
      if( null == excel )
      {
        LabUtils.ErrorMsg( "Failed to get or start Excel." );
        return IExternalCommand.Result.Failed;
      }
      excel.Visible = true;
      X.Workbook workbook = excel.Workbooks.Add( Missing.Value );
      X.Worksheet worksheet;
      //while( 1 < workbook.Sheets.Count )
      //{
      //  worksheet = workbook.Sheets.get_Item( 0 ) as X.Worksheet;
      //  worksheet.Delete();
      //}
      worksheet = excel.ActiveSheet as X.Worksheet;
      worksheet.Name = "Revit " + cat.Name;
      worksheet.Cells[1, 1] = "ID";
      worksheet.Cells[1, 2] = "Level";
      worksheet.Cells[1, 3] = "Tag";
      worksheet.Cells[1, 4] = LabConstants.gsSharedParamsDefFireRating;
      worksheet.get_Range( "A1", "Z1" ).Font.Bold = true;

      // since walls are not standard system families, implement and use
      // GetAllModelInstancesForACategory() instead to support both doors
      // and walls:

      //ElementSet doors = LabUtils.GetAllStandardFamilyInstancesForACategory( app, cat.Name );
      List<Element> elems = LabUtils.GetAllModelInstancesForACategory(
        app, Lab4_3_1_CreateAndBindSharedParam.Bic );
      // Get Shared param Guid
      Guid paramGuid = LabUtils.SharedParamGUID(
        app, LabConstants.gsSharedParamsGroupAPI, LabConstants.gsSharedParamsDefFireRating );
      if( paramGuid.Equals( Guid.Empty ) )
      {
        LabUtils.ErrorMsg( "No Shared param found in the file - aborting..." );
        return IExternalCommand.Result.Failed;
      }
      // Loop all elements and export each to an Excel row
      int row = 2;
      foreach( Element elem in elems ) {
        worksheet.Cells[row, 1] = elem.Id.Value; // ID
        worksheet.Cells[row, 2] = elem.Level.Name; // Level
        // Tag:
        Autodesk.Revit.Parameter tagParameter = elem.get_Parameter( BuiltInParameter.ALL_MODEL_MARK );
        if( null != tagParameter )
        {
          worksheet.Cells[row, 3] = tagParameter.AsString();
        }
        // FireRating:
        Parameter parameter = elem.get_Parameter( paramGuid );
        if( null != parameter )
        {
          worksheet.Cells[row, 4] = parameter.AsDouble();
        }
        ++row;
      }
      return IExternalCommand.Result.Succeeded;
    }
  }
  #endregion // Lab4_3_2_ExportSharedParamToExcel

#Region "Lab4_3_2_ExportSharedParamToExcel"
''' <summary>
''' 4.3.2 Export all door ids and FireRating param values to Excel.
''' </summary>
Public Class Lab4_3_2_ExportSharedParamToExcel
    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

        ' Launch Excel (same as in Lab 4_2, so we really should have better created some utils...)
        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.Add()
        Dim worksheet As MsExcel.Worksheet
        Do While workbook.Sheets.Count > 1
            worksheet = workbook.Sheets.Item(1)
            worksheet.Delete()
        Loop
        worksheet = excel.ActiveSheet
        worksheet.Name = "Revit Doors"
        ' Write the header row
        worksheet.Cells(1, 1).Value = "ID"
        worksheet.Cells(1, 2).Value = "Level"
        worksheet.Cells(1, 3).Value = "Tag"
        worksheet.Cells(1, 4).Value = gsSharedParamsDefFireRating
        excel.Rows("1").Font.Bold = True

            ' Use our utility from LabUtils to get all Doors
            Dim doors As List(Of Revit.Element)
            doors = LabUtils.GetAllModelInstancesForACategory(app, Lab4_3_1_CreateAndBindSharedParam.Bic)

        ' Get Shared param Guid
        Dim paramGuid As Guid = LabUtils.SharedParamGUID( _
          app, gsSharedParamsGroupAPI, gsSharedParamsDefFireRating)
        If paramGuid.Equals(Guid.Empty) Then
            MsgBox("No Shared param found in the file !? - aborting...")
            Return IExternalCommand.Result.Failed
        End If

        ' Loop all doors and export each to an Excel row
        Dim door As Revit.Element
        Dim row As Integer = 2
        For Each door In doors

            'ID
            worksheet.Cells(row, 1).Value = door.Id.Value

            'Level
            worksheet.Cells(row, 2).Value = door.Level.Name

            'Tag
            Dim tagParameter As Autodesk.Revit.Parameter = _
             door.Parameter(Autodesk.Revit.Parameters.BuiltInParameter.ALL_MODEL_MARK)
            If Not (tagParameter Is Nothing) Then
                worksheet.Cells(row, 3).Value = tagParameter.AsString
            End If

            '*FireRating*
            Dim parameter As Autodesk.Revit.Parameter = door.Parameter(paramGuid)
            If Not (parameter Is Nothing) Then
                worksheet.Cells(row, 4).Value = parameter.AsDouble
            End If

            row = row + 1

        Next

        Return IExternalCommand.Result.Succeeded
    End Function
End Class

#End Region

Compile the code and update Revit.ini. Before running this command, add some doors to the model and set their FireRating parameters. You may also save the file for use in the next command.