iOS NavigationController问题处理

• 隐藏返回按钮
  ViewController.navigationItem.hidesBackButton = true

• 隐藏返回按钮文字
  navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: UIBarButtonItemStyle.plain, target: nil, action: nil)

• 如果使用上面的方法依然有返回文字，把上面的代码放进viewWillAppear方法中。

• 导航栏标题不见了
  如果确认已经在控制器中设置了title，并且NavigationBar也可见，但是还是看不到标题。试试下面的代码：
  navigationBar.isTranslucent = false

• 在导航控制器中临时插入控制器

  var controllers = navigationController!.viewControllers
  controllers.insert(newController, at: controllers.index(of: index)!)
  navigationController?.viewControllers = controllers
  

• 替换根控制器

   var viewControllers = navigationController?.viewControllers
   viewControllers?.removeAll()
   viewControllers?.append(self)
   if let childControllers = viewControllers {
        navigationController?.viewControllers = childControllers
    }
  

• 移除特定的控制器

  var viewControllers = navigationController?.viewControllers
  viewControllers?.remove(at: index)
  navigationController?.viewControllers = viewControllers