设置self为导航控制器的代理,实现代理方法,在将要显示控制器中设置导航栏隐藏和显示,使用这种方式不仅完美切合滑动返回手势,同时也解决了切换tabBar的时候,导航栏动态隐藏的问
题.

@interface WLHomePageController () <UINavigationControllerDelegate>

@end

@implementation WLHomePageController

pragma mark - lifeCycle

• (void)viewDidLoad {
  [super viewDidLoad];

  // 设置导航控制器的代理为self
  self.navigationController.delegate = self;
  }

pragma mark - UINavigationControllerDelegate

// 将要显示控制器

• (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
  // 判断要显示的控制器是否是自己
  BOOL isShowHomePage = [viewController isKindOfClass:[self class]];

  [self.navigationController setNavigationBarHidden:isShowHomePage animated:YES];
  }