iOS power button, can the event of touching it be determined?

I'd like to know if there's a way to determine if the power button was hit to "clos开发者_运维技巧e" the screen on the device.

Is there a way to determine this? I cannot use private api's.

I don't think you can tell if the button is pressed directly without using private APIs, however you might be able to use the applicationWillResignActive: method of the UIApplicationDelegate protocol to do what you need to do.