IOS ---------- detects that the app enters the background or foreground, and ios ---------- app

IOS ---------- detects that the app enters the background or foreground, and ios ---------- app

When developing a player, you often need to check that the app enters the background (pause PLAYING) or enters the foreground (start playing ). The method is very simple.

1. Check that the app enters the background

// Implement this method in AppDelete-(void) applicationDidEnterBackground :( UIApplication *) application {// enter the background}

2. Check that the app enters the foreground

// Implement this method in AppDelete-(void) applicationDidBecomeActive :( UIApplication *) application {// this method is called when the app starts or enters the foreground from the background}-(void) applicationWillEnterForeground :( UIApplication *) application {// This method will be called when the app enters the foreground from the background}

3. Use the notification to listen to the app in the Controller to enter the foreground or background

// This method is called when the app is started or the app enters the foreground from the background [[nsicationcenter center defacenter center] addObserver: self selector: @ selector (applicationBecomeActive) name: UIApplicationDidBecomeActiveNotification object: nil] // when the app enters the foreground from the background, this method will be called [[nsicationcenter center defacenter center] addObserver: self selector: @ selector (applicationBecomeActive) name: UIApplicationWillEnterForegroundNotification object: nil]; // Add the observer [[nsnotifcenter center defacenter center] addObserver: self selector: @ selector (applicationEnterBackground) name: UIApplicationDidEnterBackgroundNotification object: nil] for the app to enter the background.