[iOS]nav设置笔记

- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    
    //设置导航栏背景图片为一个空的image，这样就透明了
    [self.navigationController.navigationBar setBackgroundImage:[[UIImage alloc] init] forBarMetrics:UIBarMetricsDefault];

    //去掉透明后导航栏下边的黑边
    [self.navigationController.navigationBar setShadowImage:[[UIImage alloc] init]];
}

    self.navigationController.navigationBar.translucent = YES;
    [self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
    
    self.navigationController.navigationBar.barTintColor = [UIColor orangeColor];
    self.navigationController.navigationBarHidden = YES;