如何知道iOS设备是否在后台进程中休眠

Question

I have a application running in background and I need to know if device is sleeping in order to start a sincronisation process, but I didn't find information about this.

Does anyone know if it is posible and how do it?

Thanks.

Answer 1

You cannot know if the device is asleep because you have no control over the OS.

You can, otherwise, use the App Delegate method:

- (void)applicationWillResignActive:(UIApplication *)application
{
    //your code goes here
}

if you want to wait till your app goes to background

Answer 2

I believe you can't do this using public API. The only thing which you can check whether your application is active or in background (using AppDelegate callbacks). And as Luke pointed out in comments, checking whether device "falls asleep" isn't iOS best design practice.

There are some private API's to do what you want, you can look at following questions:

Is there a way to check if the iOS device is locked/unlocked?

Detect screen on/off from iOS service

However, you should be aware that your app won't be accepted in AppStore in such case.