You can turn off the display by enabling the proximity monitoring. It will automatically turn off the screen, like in the Phone app, by placing the phone near your ears or by placing a finger over the IR sensor at the top of the phone.
[UIDevice currentDevice].proximityMonitoringEnabled = YES;
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…