自定义全局导航的样式

@interface EYNavigationController ()

@end

@implementation EYNavigationController

• (void)initialize
  {
  if (self == [EYNavigationController class]) {

    //隐藏导航栏分割线
    [[UINavigationBar appearance] setShadowImage:[UIImage new]];
    //设置导航栏背景颜色
    [UINavigationBar appearance].barTintColor=kNavBackColor;
    //设置导航栏标题 大小 颜色
    NSDictionary * navigationTitleAttDic = @{NSFontAttributeName:[UIFont systemFontOfSize:18],NSForegroundColorAttributeName:UIColorFromRGB(74,74,74)};
    [[UINavigationBar appearance] setTitleTextAttributes:navigationTitleAttDic];
  

  }
  }

• (void)viewDidLoad {
  [super viewDidLoad];

  self.navigationBar.translucent=NO;

}

• (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
  {
  if (self.viewControllers.count > 0) { // 此时push进来的viewController是第二个子控制器
  // 自动隐藏tabbar
  viewController.hidesBottomBarWhenPushed = YES;

    if (viewController.navigationItem.leftBarButtonItem == nil) {
        
        UIImage * backImage =[[UIImage imageNamed:@"ic_back"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
        viewController.navigationItem.leftBarButtonItem =[[UIBarButtonItem alloc] initWithImage:backImage style:UIBarButtonItemStylePlain target:self action:@selector(popself)];
    }
  

  }
  // 调用父类pushViewController，self.viewControllers数组添加对象viewController
  [super pushViewController:viewController animated:animated];
  }

• (void)popself
  {
  // 这里要用self，不能用self.navigationViewController，因为self本身就是导航控制器对象，self.navigationViewController是nil
  [self popViewControllerAnimated:YES];
  }