2016 -1 -3 导航控制器的学习

- (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window
    self.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.
}