AEC DevBlog

Accessing Element IDs of Elements Connected to a Hub

By Saikat Bhattacharya

Hub class, as the Revit API chm file states, represents a connection between two or more Autodesk Revit Elements. So rather than connecting the two elements directly, the connection is created between two Hubs. Elements connected via a Hub do not refer directly to each other - they each refer to the Hub that keeps all the connectivity information. And the class is contained in the Autodesk.Revit.DB.Structure namespace.

To access the element Ids of the elements that are connected to a Hub, the approach is to use the connectors using the ConnectorManager from a given Hub and then use the AllRefs to get access to all the connected connectors and use the Owner property on each of the linked/joined connectors to get access to the elements that are connected. The code snippet illustrates this approach.

using System;

using System.Collections.Generic;

using System.Text;

using System.Linq;

 

using Autodesk.Revit.Attributes;

using Autodesk.Revit.DB;

using Autodesk.Revit.UI;

 

namespace Revit.SDK.Samples.HelloRevit.CS

{

  [Transaction(TransactionMode.Manual)]

  public class Command : IExternalCommand

  {

    public Result Execute(ExternalCommandData commandData,

      ref string message,

      ElementSet elements)

    {

      UIApplication uiApp = commandData.Application;

      Document doc = uiApp.ActiveUIDocument.Document;

 

      FilteredElementCollector coll = new FilteredElementCollector(doc);

      String str = String.Empty;

      foreach (Autodesk.Revit.DB.Structure.Hub hub

        in

        coll.OfClass(typeof(Autodesk.Revit.DB.Structure.Hub)))

      {

        if (null != hub)

        {

          ConnectorManager mgr = hub.GetHubConnectorManager();

          foreach (Connector conn in mgr.Connectors)

          {

            ConnectorSet joinedConnectors = conn.AllRefs;

            foreach (Connector joinedConn in joinedConnectors)

            {

              str = str + "Hub (Id) "

                + hub.Id.ToString()

                + " is connected to Element (Id) "

                + joinedConn.Owner.Id.ToString()

                + "\n";

            }

 

          }

        }

      }

      TaskDialog.Show("Hub connection details", str);

 

      return Result.Succeeded;

    }

  }        

}

The output of the code:

Deleting a Collection of Elements/Families: Alternative Approach

By Saikat Bhattacharya

This post is in continuation to the existing blog post on this topic - Deleting a Collection of Elements/Families: The Correct Approach.

 
As you might have noticed in the previous blog post on this topic, the unexpected behavior is due to deleting (or infact any changes to the Element table in Revit’s database) during any active iteration itself. This typically affects FilteredElementIterator, FilteredElementIdIterator, and foreach loops over the FilteredElementCollector.

One approach that was mentioned in the previous post was to collect all the elements that fit the criteria and then performing the delete after the iteration is completed. If the deletion has to happen during the iteration itself, the other approach is to use use FilteredElementCollector.ToElements(), ToElementIds(), or LINQ methods like ToList<Type>() to get a standalone collection, then iterate that collection. The following code snippet illustrates the alternative approach.

using System;

using System.Collections.Generic;

using System.Text;

using System.Linq;

 

using Autodesk.Revit.Attributes;

using Autodesk.Revit.DB;

using Autodesk.Revit.UI;

 

namespace Revit.SDK.Samples.HelloRevit.CS

{

 

  [Transaction(TransactionMode.Manual)]

  public class Command : IExternalCommand

  {

    public Result Execute(ExternalCommandData commandData,

      ref string message,

      ElementSet elements)

    {

      UIApplication uiApp = commandData.Application;

      Document doc = uiApp.ActiveUIDocument.Document;

 

      FilteredElementCollector coll =

        new FilteredElementCollector(doc)

        .OfClass(typeof(Family));

 

      using (Transaction trans = new Transaction(doc, "Delete"))

      {

        trans.Start();

        foreach (Family fam in coll.ToElements())

        {

          if (fam.FamilyCategory.Name.Equals("Generic Annotations")

            && fam.Name.Equals("XYZ"))

          {

            doc.Delete(fam);

          }

        }

        trans.Commit();

      }

      return Result.Succeeded;

    }

  }        

}

Flipping Work Plane programmatically in Revit

By Saikat Bhattacharya

How can we use the Flip Work Plane control as available in the Revit UI, using the Revit API?

The Flip Work Plane control shows up when a Work Plane-based family instance is selected and looks like this:

 

Clicking this control, flips the work plane for the selected family instance.

Using the Revit API, we can easily identify if an instance’s work plane has been flipped or not and also use the same property to flip it too (if there is a need, as was asked in the question above). The FamilyInstance.IsWorkPlaneFlipped property helps us achieve this. So with a simple case of two mass family instances in a Revit model (shows the work plane as well), with both above the work plane,:

executing the code included below shows how the work plane of the selected instance gets flipped:

The code (in which only a single line is really the crux of this post) is included below:

using System;

using System.Collections.Generic;

using System.Text;

 

using Autodesk.Revit.Attributes;

using Autodesk.Revit.DB;

using Autodesk.Revit.UI;

 

namespace Revit.SDK.Samples.HelloRevit.CS

{

 

  [Transaction(TransactionMode.Manual)]

  public class Command : IExternalCommand

  {

    public Result Execute(ExternalCommandData commandData,

      ref string message,

      ElementSet elements)

    {

      Document document = commandData.Application.ActiveUIDocument.Document;

 

      using (Transaction trans = new Transaction(document, "WorkPlane"))

      {

        trans.Start();

        foreach (FamilyInstance famInst in commandData.Application.ActiveUIDocument.Selection.Elements)

        {

          famInst.IsWorkPlaneFlipped = true;

        }

        trans.Commit();

      }

      return Result.Succeeded;

    }

  }        

}

Linking Local File from TaskDialog

By Saikat Bhattacharya

We have tried to create a link in the footer of a task dialog, which when clicked will open up a text file in the local system. The Footer did show up as a link to the text file but that did not seem to work. When the same Footer link is a URL or link to even a HTML file in the local system, it does work fine.

As a workaround to opening up a text file (say log file) from the TaskDialog from the Footer, we can use the CommandLinks to open up the text file using Process.Start(). The following code snippet shows how to use CommandLinks to open up a local text file.

using System;

using System.Collections.Generic;

using System.Text;

 

using Autodesk.Revit.Attributes;

using Autodesk.Revit.DB;

using Autodesk.Revit.UI;

 

namespace Revit.SDK.Samples.HelloRevit.CS

{

 

  [Transaction(TransactionMode.Manual)]

  public class Command : IExternalCommand

  {

    public Result Execute(ExternalCommandData commandData,

      ref string message,

      ElementSet elements)

    {

 

      TaskDialog myDialog = new TaskDialog("Task Dialog Options");

 

      myDialog.MainIcon = TaskDialogIcon.TaskDialogIconWarning;

 

      myDialog.MainInstruction =

        "Main instruction: This is Revit Task Dialog";

      myDialog.MainContent =

        "Main content: You can add detailed description here.";

 

      myDialog.CommonButtons =

        TaskDialogCommonButtons.Yes

        ^ TaskDialogCommonButtons.No

        ^ TaskDialogCommonButtons.Cancel;

      myDialog.DefaultButton = TaskDialogResult.Yes;

 

      myDialog.ExpandedContent =

        "Expanded content: controlled by Show/Hide button";

 

      myDialog.VerificationText =

        "Verification: Do not show this message again comes here";

 

      myDialog.FooterText =

        "Footer:<a href=\"http://www.autodesk.com\">Autodesk</a>";

 

      myDialog.AddCommandLink(

        TaskDialogCommandLinkId.CommandLink1,

        "Command Link 1",

        "description 1");

 

      myDialog.AddCommandLink(

        TaskDialogCommandLinkId.CommandLink4,

        "See Log File", "");

 

      TaskDialogResult res = myDialog.Show();

      if (TaskDialogResult.CommandLink4 == res)

      {

        System.Diagnostics.Process process =

          new System.Diagnostics.Process();

        process.StartInfo.FileName = @"C:\Temp\Log.txt";

        process.Start();

      }

      return Result.Succeeded;

    }

  }        

}

Alternatively, the local log file, if saved in HTML format, could be directly opened up from the Footer too.

Naming Rules and Prefixes for Multiple Image Exports in Revit

By Saikat Bhattacharya

Using the Document.ExportImage() API, when multiple views are exported as images, the images names follow the given naming convention:

[FileName]-[ViewType]-[ViewName].[image format]

This naming convention is the same DWG export file names. You can read up more on this topic in Jeremy Tammik’s blog-post here: DWG Export Filename

Close Revit from the API

By Augusto Goncalves

This is possible using SendMessage with WM_CLOSE parameter. There are two tricks here: first, DLLImport the method from user32.dll, second get Revit windows handle.

For the first, there is a good source of those methods at PInvike.NET website. For this case, we need the SendMessage header. For the second, there is a good post at The Builder Coder blog.

Finally, the code will look like:

[Transaction(TransactionMode.Manual)]

public class AdskCommand : IExternalCommand

{

  public Result Execute(

      ExternalCommandData commandData,

      ref string message,

      ElementSet elements)

  {

    // send the message to close

    SendMessage(RevitWndHandle,

      WM_CLOSE,

      IntPtr.Zero, IntPtr.Zero);

 

    return Result.Succeeded;

  }

 

  // the value for close

  static uint WM_CLOSE = 0x10;

 

  // Use P/Invoke to DLLImport

  [DllImport("user32.dll",

    CharSet = CharSet.Auto,

    SetLastError = false)]

  static extern IntPtr SendMessage(

    IntPtr hWnd, UInt32 Msg,

    IntPtr wParam, IntPtr lParam);

 

  // singleton to store Revit handle

  static IntPtr _hWndRevit = IntPtr.Zero;

 

  // get Revit handle

  private static IntPtr RevitWndHandle

  {

    get

    {

      if (_hWndRevit == IntPtr.Zero)

      {

        System.Diagnostics.Process[] processes

          = System.Diagnostics.Process.

          GetCurrentProcess();

 

        if (0 < processes.Length)

        {

          _hWndRevit = processes[0].MainWindowHandle;

        }

      }

      return _hWndRevit;

    }

  }

}

Annotating with Family Instance Parameter data with IndependentTag in Revit

By Saikat Bhattacharya

While creating IndependentTags for elements in a Revit model, you might have noticed that the IndependentTag.TagText() method is read-only. The label for this tag is picked up, by default, by the Type parameter. For instance, for any given wall, when Document.NewTag() method is used to create a new IndependentTag, it picks up the value of the Type Mark parameter which is contained in the Wall Type.

If you wish to use the Wall Instance parameter value instead (say Mark parameter) for the tag, you can do that from the Revit User Interface (UI). You can do this by editing the Tag family and select the Label in it. This brings up the parameters of the Label in the Family Editor mode and at this point, we can click the Edit button on the Label parameter of the Label. This brings up a dialog called Edit Label in which we can set the specific Instance parameter you want to use to set the Tag text (Mark parameter in this case), instead of the default Type parameter. The screenshot below shows the dialog I am referring to here:

After reloading the Tag family in the model, any new tags created will use this specific Instance parameter value for its text.

Using the API, it does not seem like we can edit the Label of a Tag family. So as an alternative, we can work with a model/template which already has the tag families configured (as per the specific Instance parameter you want to use) and also loaded in the model. Consequently any API calls to NewTag() should use the configured tags.

Accessing System Definition Properties from a Duct in AutoCAD MEP

By Saikat Bhattacharya

How can we access the System Definition of a Pipe or  Duct or Fitting using the AutoCAD MEP .NET API?

Each of these entities expose the SystemId which can be used to access the System Definition that these entities are assigned to. Once we have access to the System Definition of the, say, Duct, we can directly access the Name, Label Name, etc.

  [Autodesk.AutoCAD.Runtime.CommandMethod(

      "DuctSD", CommandFlags.Modal)]

  public void DuctSD()

  {

    Database db = HostApplicationServices.WorkingDatabase;

    using (Transaction trans =

      db.TransactionManager.StartTransaction())

    {

      PromptEntityOptions peo =

        new PromptEntityOptions("Pick Duct");

 

      peo.SetRejectMessage("\nObject must be of type Duct.");

      peo.AddAllowedClass(typeof(Duct), true);

 

      Autodesk.AutoCAD.EditorInput.Editor ed =

        Autodesk.AutoCAD.ApplicationServices

        .Application.DocumentManager.MdiActiveDocument.Editor;

 

      PromptEntityResult per = ed.GetEntity(peo);

      Duct duct =

        trans.GetObject(per.ObjectId, OpenMode.ForRead)

        as Duct;

 

      SystemDefinition dsd = (SystemDefinition)

        db.TransactionManager.GetObject(

        duct.SystemId, OpenMode.ForRead, false);

 

      System.Windows.Forms.MessageBox.Show(

        "Name: " + dsd.Name);

      System.Windows.Forms.MessageBox.Show(

        "Label Name : " + dsd.LabelName);

      System.Windows.Forms.MessageBox.Show(

        "Alternate Name: " + dsd.AlternateName);

 

      trans.Commit();

    }

  }

Accessing Linked File Path Information using Revit .NET API

By Saikat Bhattacharya

Using the Revit API, I have been trying to determine, whether a linked RVT file or an imported DWG file has a relative or absolute path. This information is displayed in the Manage Links dialog, but how can we access this information via the API?

In the Revit API (since Revit 2012), we have the following APIs to help with this exact requirement -
 
PathType : The path type of the link (relative, absolute, or server). 
GetPath() : Gets the path of the link, relative or absolute according to the link's settings