Choosers and the Application Execution Model

Recall from Chapter 3 that when tombstoned, your app is terminated, and therefore all regular CLR event subscriptions are discarded. Choosers use a subscription model that relies on CLR events, and using a chooser can lead to your app being tombstoned. To contend with this, the chooser infrastructure has some interesting plumbing that allows it to survive tombstoning and to reinstate subscriptions to the ChooserBase.Completed event when an app is reactivated.