/*    传感器的使用： 1.注册一个传感器通知；    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(stateChange:) name:@"UIDeviceProximityStateDidChangeNotification" object:nil]; 2，设置传感器的proximityMonitoringEnabled属性为YES;  */- (void) toggle: (id) sender{	BOOL isIt = [UIDevice currentDevice].proximityMonitoringEnabled;//判断传感器是否是启动的	NSString *title = isIt ? @"Enable" : @"Disable";	self.navigationItem.rightBarButtonItem = BARBUTTON(title, @selector(toggle:));	[UIDevice currentDevice].proximityMonitoringEnabled = !isIt;//改变传感器状态		self.log = [NSMutableString string];	[self doLog:@"You have %@ the Proximity sensor.", isIt ? @"disabled" : @"enabled"];	if (!isIt) [self doLog:@"View state changes on the debugger consoler as the screen is not readable when blanked."];}- (void) stateChange: (NSNotification *) notification{    NSLog(@"notification.userinfo:%@",notification.userInfo);	NSLog(@"The proximity sensor %@", [UIDevice currentDevice].proximityState ? @"will now blank the screen" : @"will now restore the screen");}- (void) viewDidLoad{	self.navigationController.navigationBar.tintColor = COOKBOOK_PURPLE_COLOR;	self.navigationItem.rightBarButtonItem = BARBUTTON(@"Enable", @selector(toggle:));	    //注册传感器通知	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(stateChange:) name:@"UIDeviceProximityStateDidChangeNotification" object:nil];}