C# processing queue in Silverlight 4

I have the need to create a queue-based system where multiple threads will add acti开发者_StackOverflowons to be processed by the queue.

Sounds simple enough, but my actions will be asynchronous (with animations) so I do not want to start the next action in the queue until the animation of the previous action is completed.

How could I do this?

You can make an IAction interface with an Execute method and a Completed event.

You can then make a queue of IActions and pop and Execute the next item in the Completed handler for the current item.

You can even make an iterator method that yield returns IActions and have the queue call MoveNext() after each IAction finishes.

EDIT: For example:

class ActionEnumerator : IAction {
    readonly IEnumerator<IAction> enumerator;
    public ActionEnumerator(IEnumerator<IAction> enumerator) {
        this.enumerator = enumerator;
    }

    public void Execute() {
        //If the enumerator gives us another action,
        //hook up its Completed event to continue the
        //the chain, then execute it.
        if (enumerator.MoveNext()) {
            enumerator.Current.Completed += delegate { Execute(); };
            enumerator.Current.Execute();
        } else     //If the enumerator didn't give us another action, we're finished.
            OnCompleted();
    }
}

IEnumerator<IAction> SomeMethod() { 
    ...
    yield return new SomeAction();
    //This will only run after SomeAction finishes
    ...
    yield return new OtherAction();
    ...
}