iphone开发基础教程 第11章例程的问题

z在《iphone开发基础教程》第11章的例子程序 Persistence第一版用到了这段程序

UIApplication *app = [UIApplication sharedApplication];
[[NSNotificationCenter defaultCenter] addObserver:self 
  selector:@selector(applicationWillTerminate:)
  name:UIApplicationWillTerminateNotification
    object:app];

书上说按home后 程序会触发 UIApplicationWillTerminate，但实际上按home键触发的是UIApplicationDidEnterBackgroundNotification

书上那样写是因为UIApplicationWillTerminateNotification 是sdk3.0时候的 home事件 而4.0以后直接点home为 UIApplicationDidEnterBackgroundNotification事件，所以把 UIApplicationWillTerminateNotification改为 UIApplicationDidEnterBackgroundNotification即可。

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