How to make a task queue with a callback in C#?

Question

.NET

I want to do something like this in the code:
I want to add to the job queue (values) at any time

var que = new CallbackQueque<string>();
que.doTask += (str, callback) => { doSomeWork(); callback(); }; 
que.Add("one");
que.Add("two");
//в любое время
que.Add("three");

Tasks are executed in order, but the next one is moved only when the callback is fired.
What are the ready-made solutions for this and what does it look like?
Thank you!

Answer 1

ObservableCollection<T>