FAQ: Revit Macros

This section answers frequently asked questions about Revit macros.

Question	Answer
Why do I continue seeing the message "do you trust the authors of files in this folder" and how can I stop this message from appearing?	The message comes from VSCode and is part of Microsoft's "Workspace Trust" program to improve security. To stop the message from appearing: Launch "Manage Workspace Trust" setting in VSCode. At the bottom of the window, click "Add Folder". Select the following path to trust: C:\ProgramData\Autodesk\Revit\Macros\2025\Revit\AppHookup Note: "2025" refers to the year of Revit you are working with. Change as needed.
I was expecting to see my newly created macro listed in the Macro Manager's categorized list, but it is not there. Why?	You must successfully build the macro project in the Revit macro IDE (use the Build menu) before your new macros will appear in the Macro Manager.
Do I need to add RevitAPI.dll and RevitAPIUI.dll as references when writing a new macro?	No. You do not need to reference RevitAPI.dll and RevitAPIUI files because this step was completed for you. A Revit macro project uses both as required references. See Restore RevitAPI.dll and RevitAPIUI.dll.
Do I need to edit my Revit.ini files?	No. Revit macros are automatically registered to appear in the macro manager without any further modification to the system.
In the Revit macro IDE, I deleted a macro by removing its method in the This*.cs file or This*.vb file. However, the deleted macro's name still appears when I open the Macro Manager's categorized list again. How do I clear the name from the list?	You must build your edited project successfully before Macro Manager recognizes the removal.
What should I include in the startup and shutdown methods: Module_Startup and Module_Shutdown?	The Module_Startup method is called when a module loads and Module_Shutdown is called when a module unloads. For Application-level macro modules, Module_Startup is called when Revit starts and Module_Shutdown is called when Revit shuts down. For Document-level macro modules, Module_Startup is called when a Revit project opens and Module_Shutdown is called when the project document closes. Module_Startup and Module_Shutdown will also be called when the macro project is rebuilt. You can add your initializing code in the Module_Startup methods and do the cleanup work in Module_Shutdown methods. For example, you can register event handlers at start up and unregister them at shutdown (which is the recommended way).
How and why should I register and unregister my Revit event handler?	As noted previously, the recommended way to do this in the Revit IDE is to register event handlers in the *_Startup method and unregister them in the *_Shutdown method. Every macro will be loaded and unloaded dynamically. When you debug a macro, if the event handler is not properly unregistered, Revit may call a wrong method (maybe an invalid memory address). Although the Revit IDE may prevent Revit from crashing in this scenario, any event handlers that are not properly unregistered may cause performance issues during your current Revit session.
I have a dialog that does not seem to work correctly and is causing issues with Revit.	Modeless dialogs operating outside the scope of a running API callback may cause problems. It is recommended that you avoid such callbacks to prevent instability in Revit.
I want to experiment with the Startup and Shutdown methods and an event handler. Can you show me an example?	The following sample code shows how to register an OnDocumentNewed event handler, which will automatically launch a message box when a new Revit project is created. Note: One of the macro samples provided on the Revit SDK may show an example of a document-level event handler's startup and shutdown. This FAQ shows Application-level event handler examples. Please note that all API events can be accessed by the Revit IDE in 2011. Events prior to 2011 were removed. The following examples show the new events.

C# Example, Application-level:

private void Module_Startup(object sender, EventArgs e)
{
   this.Application.DocumentOpened
      += new EventHandler<Autodesk.Revit.DB.Events.DocumentOpenedEventArgs>(Application_DocumentOpened);
}

private void Module_Shutdown(object sender, EventArgs e)
{
   this.Application.DocumentOpened
      -= new EventHandler<Autodesk.Revit.DB.Events.DocumentOpenedEventArgs>(Application_DocumentOpened); 
}

void Application_DocumentOpened(object sender, Autodesk.Revit.DB.Events.DocumentOpenedEventArgs e)
{ 
   System.Windows.Forms.MessageBox.Show("message here");
}