设置导航条标题的颜色

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    
    ViewController *view=[[ViewController alloc]init];
    UINavigationController *nav=[[UINavigationController alloc]initWithRootViewController:view];
    self.window.rootViewController=nav;
    
    
    return YES;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    self.view.backgroundColor=[UIColor whiteColor];
    
    self.title=@"I love you";
    
    //改变导航条标题的颜色为红色
    [self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor redColor]}];
    
}