Apple Watch app入口点

Question

In xcode you need to specify the initial interface controller for the watch app, which is the entry point of the watch app, shown first when you open it.

But is it shown every time you open the watch app? For example you open a watch app, navigate to a page, close it, and open it again. Does it open on the page you were last time (like on iOS), or again on the first interface controller?

According to apple documentation :

Normally, WatchKit displays the first interface controller in the sequence initially.

Well, normally is not every time. I looked through watch app videos from the watch presentation event, but there wasn't a case when they opened an app twice.

Answer 1

That's a great question!

Main Entry Point

First off, you can certainly avoid showing that MainInterfaceController each time. See this thread for more information where I detail exactly how to use that entry point to launch the appropriate set of InterfaceController objects.

Watch Extension Lifecycle

It is VERY important to understand what the expected lifecycle of a Watch Extension actually is. It will only run while the user has the Watch up and is running your app. This will generally be 1-5 seconds (opinionated value). As soon as the user lowers their wrist, your Watch Extension will be terminated completely. Therefore, it is going to be restarted every time at the same entry point. This means that you need to track your app state if you want to launch a different page set in the MainInterfaceController .

Hopefully that helps shed some light.

Answer 2

If your WatchKit extension is still running, it will pick up where you left off. If not, and everything has been dumped out of memory, it should start again with your initial interface controller.