ios - issue in navigation bar not hiding in another view controller -

i have used code in app delegate making breathdatetableviewcontroller rootview controller

- (bool)application:(uiapplication *)application didfinishlaunchingwithoptions:(nsdictionary *)launchoptions {      name =[[nsstring alloc]init];     birthdate =[[nsstring alloc]init];     phone =[[nsstring alloc]init];     email =[[nsstring alloc]init];     image =[[nsstring alloc]init];      birthdatetableviewcontroller =[[birthdatetableviewcontroller alloc]initwithnibname:@"birthdatetableviewcontroller" bundle:nil];      navcontroller1 = [[[uinavigationcontroller alloc]initwithrootviewcontroller:birthdatetableviewcontroller]autorelease];      [window addsubview:navcontroller1.view];     [window makekeyandvisible];       [fbprofilepictureview class];       [[uiapplication sharedapplication]setstatusbarstyle:uistatusbarstyleblackopaque];       self.databasename = @"birthdatedatabase.sqlite";     nsarray *documentpaths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);     nsstring *documentdir = [documentpaths objectatindex:0];     self.databasepath = [documentdir stringbyappendingpathcomponent:self.databasename];     [self createandcheckdatabase];     //  sleep(5);      if (sqlite3_open([[self datafilepath] utf8string], &database1) != sqlite_ok)     {         sqlite3_close(database1);         nslog(@"failed open db.");     }     else         nslog(@"open db");       return yes; } 

so solving problem try remove navigation bar , putting following code make brithdatetableviewcontroller root view controller

self.window = [[uiwindow alloc] initwithframe:[[uiscreen mainscreen] bounds]];     // override point customization after application launch.     self.birthdatetableviewcontroller = [[birthdatetableviewcontroller alloc] initwithnibname:@"birthdatetableviewcontroller" bundle:nil];     self.window.rootviewcontroller = self.birthdatetableviewcontroller;     [self.window makekeyandvisible]; 

but when use going in brithdatetableviewcontroller not working

so lets stick did before how can negivation bar should display when in rootview should hide when goes viewcontroller , viewcontroller have there own nevigationbar , buttons.

i tried hide in viewcontroller , thats not working here.

please suggest should come on this?

in viewcontroller

- (void)viewwillappear:(bool)animated {     // if wnat navigation bar     [self.navigationcontroller setnavigationbarhidden:no];     // else if don't want     [self.navigationcontroller setnavigationbarhidden:yes]; }