navigationController返回到某一制定页面

假设需要返回到的控制器为firstViewController
代码如下：

    for i in 0..<(self.navigationController?.viewControllers.count)! {
                    if self.navigationController?.viewControllers[i].isKindOfClass(firstViewController) == true {
                        
                        _ = self.navigationController?.popToViewController(self.navigationController?.viewControllers[i] as! firstViewController, animated: true)
                        break
                    }
                }

在相应的方法中这样写就可以返回到指定的页面了