- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {// Override point for customization after application launch.UIWindow *window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];oneViewController *oneVC =  [[oneViewController alloc] init];oneVC.view.backgroundColor =[UIColor grayColor];//  设置导航控制器的根控制器UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:oneVC];
//    设置window为可见[window makeKeyAndVisible];
//    将AppDelegate的window属性设置为自定义的windowself.window = window;
//    设置窗口的根控制器为导航控制器window.rootViewController = nav;return YES;
}

- (void)viewDidLoad {[super viewDidLoad];
//    设置标题self.navigationItem.title = @"第一个";UIBarButtonItem *camerBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemBookmarks target:nil action:nil];UIBarButtonItem *secondBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:nil action:nil];
//    self.navigationItem.leftBarButtonItem = camerBtn;self.navigationItem.leftBarButtonItems =@[camerBtn,secondBtn];
//    设置返回按钮
#warning 这里是给下一个viewController设置的UIBarButtonItem *backItem = [[UIBarButtonItem alloc] initWithTitle:@"返回" style:UIBarButtonItemStylePlain target:nil action:nil];self.navigationItem.backBarButtonItem =backItem;
}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}