Is there a way to check if the iOS device is in sleep mode?

Question

Hi All, I have used GPS location updates in my application. I want to detect if the iOS device is in sleep mode so that I can turn off the GPS and optimize the battery use. I have already tried pausesLocationupdates in iOS 6, but it does not work as desired.I want to turn off the GPS as soon as the device goes to sleep mode. Is there any way to achieve this functionality ?Thanks in advance.

msuper69 · Answer

If iOS goes to sleep, your app will receive a notification automatically.What your app does after that is whatever you&#x27;ve coded it to do.When iOS wakes up, your app will also receive a notification automatically.What your app does after that is whatever you&#x27;ve coded it to do.iOS handles powering up/down the various radios automatically.  You don&#x27;t have to worry about it.

Rohit_Kashyap · Answer

Thanks Michael.Could you please mention which notification will my app receive? "resignactive" will only be called when application goes to background, however I want to catch the scenario when my application is already running in the background and the device goes to sleep, the screen blackens, at that time I want to turn off the GPS, so please mention which notification will my application get in this scenario ?

msuper69 · Answer

You can&#x27;t turn off the GPS; only iOS has permission to do that.

Rohit_Kashyap · Answer

But I can pause the location updates depending on the mode of the device if I get any notification when device goes to sleep mode.This will optimize the battery use.

Rohit_Kashyap · Answer

I want to detect the lock/unlock events in the device, so far I got the darwin notifications as given below,:-(void)registerForDarwinNotif{        //Screen lock notifications    CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center                                    NULL, // observer                                    displayStatusChanged, // callback                                    CFSTR("com.apple.iokit.hid.displayStatus"), // event name                                    NULL, // object                                    CFNotificationSuspensionBehaviorDeliverImmediately);            CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center                                    NULL, // observer                                    displayStatusChanged, // callback                                    CFSTR("com.apple.springboard.lockstate"), // event name                                    NULL, // object                                    CFNotificationSuspensionBehaviorDeliverImmediately);        CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center                                    NULL, // observer                                    displayStatusChanged, // callback                                    CFSTR("com.apple.springboard.hasBlankedScreen"), // event name                                    NULL, // object                                    CFNotificationSuspensionBehaviorDeliverImmediately);             }   //My call backstatic void displayStatusChanged(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo){       NSLog(@"IN Display status changed");    // you might try inspecting the &#x60;userInfo&#x60; dictionary, to see    //  if it contains any useful info           NSLog(@"Darwin notification NAME &#x3D; %@",name);             }    I am able to get the darwin notifications when device is locked/unlocked, but the real problem is how identify between if the notification has come from locking or the unlocking of the device. Console logs are:Jan 10 11:29:01 Frost-bank LockDetectDemo[2086] &lt;Warning&gt;: IN Display status changedJan 10 11:29:01 Frost-bank LockDetectDemo[2086] &lt;Warning&gt;: Darwin notification NAME &#x3D; com.apple.springboard.lockcompleteJan 10 11:29:01 Frost-bank LockDetectDemo[2086] &lt;Warning&gt;: IN Display status changedJan 10 11:29:01 Frost-bank LockDetectDemo[2086] &lt;Warning&gt;: Darwin notification NAME &#x3D; com.apple.springboard.lockstateJan 10 11:29:01 Frost-bank LockDetectDemo[2086] &lt;Warning&gt;: IN Display status changedJan 10 11:29:01 Frost-bank LockDetectDemo[2086] &lt;Warning&gt;: Darwin notification NAME &#x3D; com.apple.springboard.hasBlankedScreenJan 10 11:29:01 Frost-bank LockDetectDemo[2086] &lt;Warning&gt;: IN Display status changedJan 10 11:29:01 Frost-bank LockDetectDemo[2086] &lt;Warning&gt;: Darwin notification NAME &#x3D; com.apple.iokit.hid.displayStatus