detect if phone screen is on/off in iOS -

i have requirement in application detect if phone screen on/off when application in background? found can possible using private framework spring board. can public apis?

thank.

try this:

in appdelegate.m

- (bool)application:(uiapplication *)application didfinishlaunchingwithoptions:(nsdictionary *)launchoptions  {     //other code     [self registerfordevicelocknotif]; }  //register notification -(void)registerfordevicelocknotif {     //screen screendisplaystatus notifications     cfnotificationcenteraddobserver(cfnotificationcentergetdarwinnotifycenter(), null, screendisplaystatus, cfstr("com.apple.iokit.hid.displaystatus"), null, cfnotificationsuspensionbehaviordeliverimmediately);      cfnotificationcenteraddobserver(cfnotificationcentergetdarwinnotifycenter(), //center                                     null, // observer                                     screenlockstatus, // callback                                     cfstr("com.apple.springboard.lockstate"), // event name                                     null, // object                                     cfnotificationsuspensionbehaviordeliverimmediately); }  //removenotification if don't need more. -(void)removefordevicelocknotif{     cfnotificationcenterremoveobserver(cfnotificationcentergetdarwinnotifycenter(), null, cfstr("com.apple.iokit.hid.displaystatus"), null);     cfnotificationcenterremoveobserver(cfnotificationcentergetdarwinnotifycenter(), null, cfstr("com.apple.springboard.lockstate"), null); }  //call methods static void screendisplaystatus(cfnotificationcenterref center, void* observer, cfstringref name, const void* object, cfdictionaryref userinfo) {     uint64_t state;     int token;     notify_register_check("com.apple.iokit.hid.displaystatus", &token);     notify_get_state(token, &state);     notify_cancel(token);     if (state) {         screenisblack = no;     }else{         screenisblack = yes;     } }  static void screenlockstatus(cfnotificationcenterref center, void* observer, cfstringref name, const void* object, cfdictionaryref userinfo) {     uint64_t state;     int token;     notify_register_check("com.apple.springboard.lockstate", &token);     notify_get_state(token, &state);     notify_cancel(token);     if (state) {         screenislocked = yes;     }     else     {         screenislocked = no;     } } 

do task when screen black screen:

if (appisbackground && (screenisblack || screenislocked) {     //do task. } 

note that, here have made screen lock status screen black, if need not, remove lock status judgement.