Question

I don’t want multiple windows, each with its own UI thread, nor events raised on a single UI thread, not background workers and notifications, none of that Invoke, BeginInvoke stuff either.

• I’m interested in a platform that allows multiple threads to update the same window in a safe manner. Something like first thread creates three buttons, the second thread another five, and they both can access them,change their properties and delete them without any unwanted consequences.
• I want safe multi-threaded access to the UI without Invoking, a platform where the UI objects can be accessed directly from any thread without raising errors like “The object can only be accessed from the thread that created it”. To let me do the synchronizing if I have to, not prevent me from cross-tread accessing the UI in a direct manner.

Answer 1

You could make a thread-safe Producer/Consumer queue of delegates.
Any thread that wants to update a UI component would create a delegate encapsulating the operations to be performed, and add it to the queue.
The UI thread (assuming all components were created on the same thread) would then periodically pull an item from the queue, and execute the delegate.