UIAlertController推送导航栏项

Question

UIAlewrtController按下导航控制器中的按钮（见图）

执行顺序：

1. on push +警报控制器已激活
2. 选择＆＃34;采取行动＆＃34;或者＆＃34;请求行动＆＃34;视图控制器ActionDetialsVC已激活。
3. 显示ActionDetialsVC
4. on ActionDetialsVC已关闭
5. iitial controlers BACK arrow move

将断点放在：

1. self.present（alert，animated：true，completion：nil）
2. 2个警报处理程序中的第一个Swift指令

这些断点之间可以看到奇怪的导航后退按钮行为。

仅在我的视图中引入警报控制器时才会出现此问题!!!!!

感谢您的帮助

问题图片：

代码：

func addPressed(_ sender: Any) {

    let alert = UIAlertController (title: "Add an Action", message: nil, preferredStyle: UIAlertControllerStyle.alert)

    let request = UIAlertAction (title: actionType.Request.Str(), style: UIAlertActionStyle.default, handler: {
        action in

        self.actionTypeTemp = actionType.Request.Str()
        self.performSegue(withIdentifier: "segueActionDetailsVC", sender: nil)
    }  )

    let take = UIAlertAction (title: actionType.Take.Str(), style: UIAlertActionStyle.default, handler: {
        action in

        self.actionTypeTemp = actionType.Take.Str()
        self.performSegue(withIdentifier: "segueActionDetailsVC", sender: nil)
    }  )

    let done = UIAlertAction (title: "Cancel", style: UIAlertActionStyle.cancel, handler: nil )

    alert.addAction(request)
    alert.addAction(take)
    alert.addAction(done)

    self.present (alert, animated: true, completion: nil)
}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "segueActionDetailsVC" {
        if let destination = segue.destination as? ActionDetailsVC {
            if let action = sender as? PActions {
                destination.actionToEdit = action
            }
            else {
                if actionTypeTemp == actionType.Request.Str() {
                    destination.relatedContact = self.contact
                    destination.title = actionType.Request.Str()
                }
                else {
                    destination.relatedContact = self.contact
                    destination.title = actionType.Take.Str()
                }
            }
        }
    }
}