Question

I have a working project, one of the screen is for example ViewController 1 – tableView. i am trying to pass data and navigate to ViewController 2 after selecting a row in ViewController 1. I added this code:

DetailViewController *dvController = [[DetailViewController alloc] initWithNibName:@"DetailView" bundle:[NSBundle mainBundle]];
dvController.selectedItem = selectedItem;
[self.navigationController pushViewController:dvController animated:YES];
[dvController release];

But its not passing to ViewController 2. I think the problem is with navigatorController.
Where should I add it? to xib file of ViewController 1? or to the mainAppDelegate – I dont want to touch it because its already working with its settings…

I declared UINavigationController *navigationController in my appDelegate

What should I check?

After some changes to to code (thanks to @Vakul Saini)
appDelegate.m:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  self.View1 = [[startSearching alloc] initWithNibName:@"StartSearching" bundle:nil];
self.currentNC = [[UINavigationController alloc] initWithRootViewController:self.View1];

//this line start the startSearching at the begining and its passing to //secondViewController
    self.window.rootViewController = self.currentNC;

// but with this line its start from the original start page but the transfer of views //doesn’t wroks

 [self.window setRootViewController: self.viewController];

appDelegate.h

@property (strong, nonatomic) startSearching *View1;
@property (strong, nonatomic) UINavigationController *currentNC;

startSearching.m

detailCon *detailCo =[[detailCon alloc] initWithNibName: @"detailView" bundle: [NSBundle mainBundle]];
[detailCon release];
UINavigation *currentNC1 = [[AppDelagate sharedInstance] currentNC];
[currentVC1 pushViewController:detailCo animated:YES];

Answer 1

Check you have a UINavigationController in your Appdelegate or not. You need to make your app rootViewController is UINavigationController
Add your UINavigationController in appdelegate

Appdelegate.h file

#import <UIKit/UIKit.h>

@class ViewController;

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) ViewController *viewController;
@property (strong, nonatomic) UINavigationController *navCon;

@end

Appdelegate.m file

#import "AppDelegate.h"
#import "ViewController.h"

@implementation AppDelegate

@synthesize window = _window;
@synthesize viewController = _viewController;
@synthesize navCon = _navCon;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
    self.navCon = [[UINavigationController alloc]initWithRootViewController:self.viewController];
    self.window.rootViewController = self.navCon;
    [self.window makeKeyAndVisible];
    return YES;
}

Where ViewController is your firstView of app.