是否有人实现了一个功能，如果用户在某个时间段内没有touch 屏幕，您会采取某个操作？我在想最好的办法.
在UIApplication中有这个有点相关的方法:
[UIApplication sharedApplication].idleTimerDisabled;
如果你有这样的东西就好了:
NSTimeInterval timeElapsed = [UIApplication sharedApplication].idleTimeElapsed;
然后我可以设置一个计时器，定期判断这个值，并在它超过阈值时采取一些措施.
希望这能解释我要找的东西.有没有人已经解决了这个问题，或者有什么 idea 你会怎么做？谢谢.
这就是我一直在寻找的答案:
让应用程序委托子类UIApplication.在实现文件中，重写sendEvent:方法，如下所示:
- (void)sendEvent:(UIEvent *)event {
[super sendEvent:event];
// Only want to reset the timer on a Began touch or an Ended touch, to reduce the number of timer resets.
NSSet *allTouches = [event allTouches];
if ([allTouches count] > 0) {
// allTouches count only ever seems to be 1, so anyObject works here.
UITouchPhase phase = ((UITouch *)[allTouches anyObject]).phase;
if (phase == UITouchPhaseBegan || phase == UITouchPhaseEnded)
[self resetIdleTimer];
}
}
- (void)resetIdleTimer {
if (idleTimer) {
[idleTimer invalidate];
[idleTimer release];
}
idleTimer = [[NSTimer scheduledTimerWithTimeInterval:maxIdleTime target:self selector:@selector(idleTimerExceeded) userInfo:nil repeats:NO] retain];
}
- (void)idleTimerExceeded {
NSLog(@"idle time exceeded");
}
其中maxIdleTime和idleTimer是实例变量.
为了使其正常工作，您还需要修改main.m以告诉UIApplicationMain使用您的委托类(在本例中为AppDelegate)作为主体类:
int retVal = UIApplicationMain(argc, argv, @"AppDelegate", @"AppDelegate");