UITabBarItem设置的title细节注意

    func addChildViewContoller(title:String,image:String,selectimage:String, vc:UIViewController)  {
        vc.tabBarItem.title=title//设置tabBarItem标签文字
        vc.tabBarItem.image=UIImage(named: image)//设置tabBarItem标签图片
        addChildViewController(vc)
    }

  func addChildViewContoller(title:String,image:String,selectimage:String, vc:UIViewController)  {
      vc.navigationItem.title=title//设置了导航条标题
      let na = UINavigationController(rootViewController: vc)
      na.tabBarItem.title=title//设置了tabBarItem标题
      addChildViewController(na)
  }

    func addChildViewContoller(title:String,image:String,selectimage:String, vc:UIViewController)  {
        vc.title=title//同时设置了导航条标题，tabarbuttom标题
        let na = UINavigationController(rootViewController: vc)
        addChildViewController(na)
    }

    func addChildViewContoller(title:String,image:String,selectimage:String, vc:UIViewController)  {
        vc.tabBarItem.title=title//设置tabarbuttom标题,只有tabBarItem的image有值时，title才会显示。否则好像无限，亲测有效
        vc.tabBarItem.image=UIImage(named: image)
        let na = UINavigationController(rootViewController: vc)
        addChildViewController(na)
    }