ios - How to change the badge of a view controller that isn't loaded? -

i have tab bar controller, has 3 view controller attached.

say start app, first view controller view out of other 3 loaded. want set badge value of third view controller isn't loaded. because want user know have notifications when open app.

is possible , how can it? have tried following:

calling view ( 1 want change badge ) class:

 notificationsviewcontroller *class = [notificationsviewcontroller alloc]init];   [class view]; 

then, in notificationsviewcontroller class, set badge 1 if app has notifications using parse:

- (void)viewdidload { [super viewdidload];  pfinstallation *currentinstallation = [pfinstallation currentinstallation]; if (currentinstallation.badge > 0) {      nsstring *badge = @"1";          [self.tabbaritem setbadgevalue:badge];       }    } 

why isn't working? how can change badge of view controller isn't loaded yet?

first, need tab bar item:

uitabbaritem *tabbaritem = [[self.tabbarcontroller.viewcontrollers objectatindex:your_index] tabbaritem]; 

then, set badge on it.

nsstring *badge = @"1"; [tabbaritem setbadgevalue:badge];