iphone待机按钮

您必须收听以下两个通知:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appLostFocus:) name:UIApplicationWillResignActiveNotification object:[UIApplication sharedApplication]];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appGotFocus:) name:UIApplicationDidBecomeActiveNotification object:[UIApplication sharedApplication]];

并妥善处理:

- (void)appLostFocus:(NSNotification*)notification
{
    NSLog(@"app lost focus");
}

- (void)appGotFocus:(NSNotification*)notification
{
    NSLog(@"app got focus");
}

- (void)applicationDidFinishLaunching:(UIApplication *)application { 

    [[UIApplication sharedApplication] setIdleTimerDisabled:YES];

//...
}