Question

I recognize this may be a duplicate post, but I want to make sure I ask this question clearly and get an answer based on my wording.

I have a collection of forms which inherit from a common visual element: MainVisualForm. This element provides me a way to know when the form is advancing of stepping backwards. What form comes next in the sequence is dependent on user action.

I currently have this code for one such event as I am testing:

form.OnNextForm += (f, ev) =>
            {
                Parameters.Vehicle = ((VehicleForm)f).SelectedVehicle;
                //FormStack.Push(Parameters.Vehicle == Vehicle.SUV
                //                ? new KeyValuePair<Type, IFormActionBehvaior>(typeof(EntertainmentForm), null)
                //                : new KeyValuePair<Type, IFormActionBehvaior>(typeof(ColorForm), null));
            };

This assignment is followed immediately by ShowDialog() which blocks the user until the Dialog form is closed.

The question is:
After the form closes does .NET wait for the EventHandler to complete before running the code which directly follows ShowDialog() or is the handler handled by a different thread?

Thanks very much in advance

Answer 1

Winforms runs in a single thread – in fact you can’t even access it from a second thread without running into trouble. Unless you create a thread yourself (or a BackgroundWorker or anything else that constitutes a thread), you’ll only ever have one thread.