Question

I have a form and several external classes (serial port, file access) that are instantiated by the form.

1) What’s the simplest way to run an instance of an external class in its own thread?

2) Is the instance’s thread automatically terminated when the form closes?

Answer 1

1) What’s the simplest way to run an instance of an external class in its own thread?

Instances of classes do not “run”. Methods do.

As such, you may want to look into the APM pattern and the BackgroundWorker class.

2) Is the instance’s thread automatically terminated when the form closes?

It depends on how the threads were started. A thread can be a background thread or a foreground thread – the latter prevents the application from terminating.