[Mono-osx] Is there a Xamarin.Mac non-modal NSAlert dialog?

[Edward Ned Harvey (mono)]

In Xamarin.Mac, I can easily create an NSAlert, and call RunModal(). The problem is, this hogs the MainThread, and blocks other things from running. For example, if a thread from ThreadPool calls InvokeOnMainThread( delegate => { do_NSAlert_modal(); } ); we'd really like the ThreadPool thread to be the only thread waiting on that dialogue.

Is there such a thing as a non-blocking alternative to running NSAlert modally? Or do I need to create some new custom window to perform this functionality?