Revit API : Revit Add-Ins with WPF

This post is about how you can implement WPF (Windows Presentation Foundation) form in Revit Add-Ins Command or Application. In this sample project we will be creating a simple Revit Add-Ins Command to display all the list of views from the current document in WPF Treeview (see figure 1.0) and I will be using Visual Studio 2017 and Revit 2019.

figure 1.0 – Views in WPF TreeView

Let’s start our project by launching Visual Studio and create a new project > choose Class Library (.Net Framework) and name it “RevitAddInsWPFSample” (figure 1.1).

figure 1.1 – Setting up the project

After this, you should be seeing namespace class window as shown in figure 1.2 below.

figure 1.2 – Project Namespace

In the Solution Explorer panel, right-click on References and Add Reference. And then, add two Revit API libraries as our project references. (figure 1.3, 1.4)

figure 1.3 – Add Reference

Click “Browse …” button on Reference Manager Window and add these libraries “RevitAPI.dll” and “RevitAPIUI.dll” from Revit Product Installation directory (the default path is C:\Program Files\Autodesk\Revit 201x\*). (figure 1.4)

figure 1.4 – RevitAPI References

Select two libraries and right-click go to properties to change local copy value.

Import library assemblies from DB, UI, and Attributes namespaces. And add the Transaction Attribute to declares the way the transaction should work. It could be either Manual or Automatic. (figure 1.5)

figure 1.5 – IExternalCommand Execute Method

Create an external command by creating an object(our “Class1” class) that implements the IExternalCommand interface. The IExternalCommand interface has one abstract method, Execute, which is the main method for external commands.

The Execute() method has three parameters:

  1. commandData (ExternalCommandData) – contains references to Application and View which are required by the external command.
  2. message (String) – error messages are returned by an external command using the output parameter message.
  3. elements (ElementSet) – any elements are added to the elements parameter, these elements will be highlighted on screen.
namespace RevitAddInsWPFSample
    public class Class1:IExternalCommand
        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
            // return result
            return Result.Succeeded;

And now we are going to add WPF window. In the Solution Explorer panel, right-click > Add > New Item…

figure 1.6 – New Item…

Select User Control (WPF) and name it “Viewer.xaml”. (figure 1.7)

figure 1.7 – User Control (WPF)

You should be seeing a big black blank window as shown in figure 1.8.

figure 1.8 – UserControl

And change “UserControl” xaml tag to “Window” tag. (figure 1.9)

figure 1.9 – UserControl tag to Window tag

Add some Window tag properties such as Height, Width, Title, WindowStartupLocation, and ResizeMode. Finally, add a GroupBox which contains our TreeView object in the Grid tag.  (figure 1.10)

figure 1.10 – Window Properties and TreeView

In the Grid tag, add a GroupBox and add a TreeView as per XAML code from figure1.10.

Next, go to “Viewer.xaml.cs” a partial class which located under Viewer.xaml. And change UserControl interface to Window as shown in figure 1.11.

figure 1.11 – Viewer.xaml.cs

Add one argument in our Viewer constructor and we will write a method, DisplayTreeViewItem,  which collects all the views from the current Revit document and display in the TreeView. Below is the code in “Viewer.xaml.cs”.

namespace RevitAddInsWPFSample
    /// <summary>
    /// Interaction logic for Viewer.xaml
    /// </summary>
    public partial class Viewer : Window
        // field
        public Document document;
        // constructor
        public Viewer(Document doc)
            // assign value to field
            document = doc;
            // display view

        public void DisplayTreeViewItem()
            // viewtypename and treeviewitem dictionary
            SortedDictionary<string,TreeViewItem> ViewTypeDictionary = new SortedDictionary<string, TreeViewItem>();
            // viewtypename
            List<string> viewTypenames = new List<string>();
            // collect view type
            List<Element> elements = new FilteredElementCollector(document).OfClass(typeof(View)).ToList();
            foreach (Element element in elements)
                // view
                View view = element as View;
                // view typename
            // create treeviewitem for viewtype
            foreach (string viewTypename in viewTypenames.Distinct().OrderBy(name => name).ToList())
                // create viewtype treeviewitem
                TreeViewItem viewTypeItem = new TreeViewItem() { Header = viewTypename };
                // store in dict
                ViewTypeDictionary[viewTypename] = viewTypeItem;
                // add to treeview

            foreach (Element element in elements)
                // view
                View view = element as View;
                // viewname
                string viewName = view.Name;
                // view typename
                string viewTypename = view.ViewType.ToString();          
                // create view treeviewitem 
                TreeViewItem viewItem = new TreeViewItem() { Header = viewName };
                // view item add to view type

First, we create a field to store the Document instance. In the Viewer Constructor, assign field value to the document which uses as an argument in our partial class constructor. And call our DisplayTreeViewItem method too. In this DisplayTreeViewItem first, we find all the ViewTypes from the current Revit document and create a first-level TreeViewItem.

Next, collect all the views from the current Revit document, for each view create a TreeViewItem and attached it as second-level TreeViewItem in their associate ViewType first-level TreeViewItem.

Now we have to call our WPF form from ” Class1.cs Execute method ” and build the project to get “RevitAddInsWPFSample.dll” file in ” bin/Debug/ ” folder. (figure1.12)(figure 1.13)

Note: if you want to make a transaction, you can only do in this “Execute method”. If you make inside WPF form, an error will be raised.

figure 1.12 – Viewer form in Class1.cs
figure 1.13 – RevitAddInsWPFSample.dll Location

For the next step, we have to create “.addin” file which is AddIn manifest located in a specific location checked by Revit when the application starts. The manifest includes information used by Revit to load and run the plug-in.

In the Solution Explorer panel, Select and right-click > Add > New Item… (figure 1.13)

add item
figure 1.14 – Add New Item for addin manifest

Select Text File , name it “RevitAddInsWPFSample.addin” and Add to the project. (figure 1.15)

figure 1.15 – RevitAddInsWPFSample.addin

Add Add-In informations to “RevitAddInsWPFSample.addin” file… Note: inside tag write your full path for “RevitAddInsWPFSample.dll”. (figure 1.16)

figure 1.16 – RevitAddInsWPFSample.dll full path in Assembly

The final step is to copy “RevitAddInsWPFSample.addin” manifest file and paste it in a specific location checked by Revit when the application starts which is “AppData\Autodesk\Revit\Addins\201x” . So, select RevitAddInsWPFSample namespace and right-click > Properties and then goes to Build Events > in the Pre-build event command line, type in xcopy /Y “$(ProjectDir)RevitAddInsWPFSample.addin” “$(AppData)\Autodesk\Revit\Addins\201x”  (figure 1.17).

figure 1.17 – Copy and Paste Manifest File

Finally, goes to Debug tab > Start external program > provide your Revit Executable file as shown in figure 1.18. This file locates inside Revit Product Installation directory (the default path is C:\Program Files\Autodesk\Revit 201x\*).

figure 1.18 – Select Revit Executable

And make sure to match this AddIns project’s .Net Framework version with Revit .Net Framework version because Revit 2019 uses .Net Framework version is 4.7 and Revit 2017,2018 use .NetFramework version 4.6.1. (figure 1.19)

figure 1.19 – Target framework version

We have finished writing our Revit AddIns project and now is the time to test it out. Click on “Start” or press “F5” to launch Revit Application that we have already set up in Debug > Start external program. After Revit Application is opened, when you see this popup window from Revit, click on “Always Load” button. (figure 1.20)

figure 1.20 – Loading Add-In

Go to the Add-Ins tab, you should be seeing our Add-Ins Command under External Tools panel. (figure 1.21)

figure 1.21 – RevitAddInsWPFSample Command

Well, that’s all for this sample project and complete source code is here.

Revit AddIns with WPF

Revit Add-Ins Development Additional Resources :

Autodesk Revit Add-Ins Sample:

Autodesk Revit Add-Ins Documentation:


16 thoughts on “Revit API : Revit Add-Ins with WPF

  1. Cree una clase independiente,pero me devuelve cero,Porque?

    I created an independent class, but it returns zero, why?

    static public SortedDictionary RellenarTreeview(Document doc,TreeView tree)


    // viewtypename and treeviewitem dictionary
    SortedDictionary ViewTypeDictionary = new SortedDictionary();


    foreach (Element elem in elements)
    // view
    View view = elem as View;
    // viewname
    string viewName = view.Name;
    // view typename
    string viewTypename = view.ViewType.ToString();
    // create view treeviewitem
    TreeViewItem viewItem = new TreeViewItem() { Header = viewName };
    // view item add to view type

    return ViewTypeDictionary;

    ViewTypeDictionary return 0



  2. Gracias por tu respuesta tan rápida ,ya lo solucione,ahora ,como puedo adicionar una imagen ?

    Thanks for your quick answer, I solved it, now, how can I add an image?


  3. I’m trying to do something very similar in a form in a macro, but having issues:

    List vftlist = new FilteredElementCollector(doc).OfClass(typeof(ViewFamilyType)).Cast().Where(a =>a.ViewFamily == ViewFamily.StructuralPlan).ToList();

    foreach (ViewFamilyType vft in vftlist)
    string s = vft.Name;
    string realviewName = “”;
    List elements = new FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Views)
    .Where(c => c.get_Parameter(BuiltInParameter.ELEM_TYPE_PARAM).AsValueString().Equals(s)).ToList();

    foreach (Element v in elements)
    realviewName = v.Name;

    TreeNode viewtypeTN = new TreeNode();
    viewtypeTN = testingTV.Nodes.Add(s);
    TreeNode viewnamemnode = new TreeNode();
    viewnamemnode = viewtypeTN.Nodes.Add(realviewName);

    I know this creates the tree node for each instance of view by its view type. If I comment out the viewnamenode and pull out the treenode to the outside, I get all the types I want, but adding the views to their respective type is creating an issue, do I have to add something else? a List and then a string array? Any help would be appreciated.


    1. I figured that top part out. so now that can select these nodes, I’m getting tripped up in bringing those selected nodes as strings into my main code to do something with them. The TreeView.SelectedNode seems to be a little different than a List or ComboBox where you can declare a public string and get the selecteditem.tostring.


      1. Thanks for your answer, I would like to practice it with the same example (REVIT ADD-INS WITH WPF), any ideas, what should I put in the Model?


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