iOS - 优雅的隐蔽导航栏

- (void)viewWillAppearBOOL)animated {
    [super viewWillAppear:animated];
    [self.navigationController setNavigationBarHidden:true animated:animated];
}
- (void)viewWillDisappearBOOL)animated {
    [super viewWillDisappear:animated];
    [self.navigationController setNavigationBarHidden:false animated:animated];
}

@property (nonatomic, copy) void(^viewWillAppearNavigationBarHandler)(BOOL animated);
- (void)viewWillAppearBOOL)animated {
    [super viewWillAppear:animated];
    if (self.viewWillAppearNavigationBarHandler) {
        self.viewWillAppearNavigationBarHandler(animated);
    } else {
        [self.navigationController setNavigationBarHidden:NO animated:animated];
    }
}

- (void)viewDidLoad {
    [super viewDidLoad];
    __weak typeof(self) weakSelf =self;
    self.viewWillAppearNavigationBarHandler = ^(BOOL animated) {
        [weakSelf.navigationController setNavigationBarHidden:YES animated:animated];
    };
}