IOS导航隐藏下边的线

 if (kIsIOS7OrLater) {
    // Close this to make normal
    self.automaticallyAdjustsScrollViewInsets = NO;
    // 透明状态栏的延伸
    self.edgesForExtendedLayout = UIRectEdgeNone;
    [self.navigationController.navigationBar setBackgroundImage:kImageWithName(@"标题栏")
                                                 forBarPosition:UIBarPositionAny
                                                     barMetrics:UIBarMetricsDefault];
  } else {
    [self.navigationController.navigationBar setBackgroundImage:kImageWithName(@"标题栏")
                                                  forBarMetrics:UIBarMetricsDefault];
  }

  // 添加上这一句，可以去掉导航条下边的shadowImage，就可以正常显示了
  self.navigationController.navigationBar.shadowImage = [[UIImage alloc] init];
  self.navigationController.navigationBar.translucent = NO;