Revit crashing when I am writing some code in ComponentManager_UIElementActivate

[nitinjambhale]

I am trying to start the Revit's Transaction in 

private void ComponentManager_UIElementActivated(object sender, Adwin.UIElementActivatedEventArgs e)

{

          Transaction transaction = new Transaction(doc, "Test"))

           transaction.Start("Test");

}

But, Revit is crashing when it hit the transaction.Start() method.

I am on Revit API 2020.

[jeremytammik · Accepted solution]

Dear Nitin,

Welcome to Revit API programming!

To get started with the Revit API, I suggest that you first of all take a look at the getting started material and work through the step-by-step instructions provided by the DevTV and My First Revit Plugin video tutorials:

http://thebuildingcoder.typepad.com/blog/about-the-author.html#2

That will explain all you need, including the answer to your question.

For a quick start, you can also check out the hello world examples in the developer guide:

http://help.autodesk.com/view/RVT/2018/ENU/?guid=Revit_API_Revit_API_Developers_Guide_Introduction_G...

A slightly more complex answer to your question is this:

All calls to the Revit API require a valid Revit API context:

• http://thebuildingcoder.typepad.com/blog/2015/08/revit-api-context-and-form-creation-errors.html
• http://thebuildingcoder.typepad.com/blog/2015/08/revit-api-context-and-form-creation-errors.html#2
• http://thebuildingcoder.typepad.com/blog/2015/12/external-event-and-10-year-forum-anniversary.html#2

Such a context is not provided by the UIElementActivated.

Therefore, you cannot use the Revit API there at all, and consequently not start a transaction either.