Swift3 Swift 3.0中UIAlertAction内部的UIAlertView？

是否可以在UIAlertAction中添加UIAlert视图

因为当我试图在UIAlertAction中添加UIAlert视图时，它说

“警告：试图显示其视图不在窗口中的对象。” 等级制度！”

这是我的密码

let myAlert = UIAlertController(title: "Title", message: "title here", preferredStyle: UIAlertControllerStyle.alert)
let okaction = UIAlertAction(title: "Okay", style: UIAlertActionStyle.default, handler:
    {
        action in
        let myViewController:ViewController = self.storyboard!.instantiateViewController(withIdentifier: "ViewController") as! ViewController

        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        let navigationController = UINavigationController.init(rootViewController: myViewController)
        appDelegate.window?.rootViewController = navigationController
        appDelegate.window?.makeKeyAndVisible()

        if (statement here == 1) {
            let myAlert = UIAlertController(title: "Title", message: "title", preferredStyle: UIAlertControllerStyle.alert)
            myAlert.addAction(UIAlertAction(title: "Okay", style: UIAlertActionStyle.default, handler: nil))
            self.present(myAlert, animated: true, completion: nil)
            return
        }
    }
)
myAlert.addAction(okaction)
self.present(myAlert, animated: true, completion: nil)

---

尝试将调用包装到函数中的第二个警报，然后调用该函数

像这样

let myAlert = UIAlertController(title: "Title", message: "title here", preferredStyle: UIAlertControllerStyle.alert)
let okaction = UIAlertAction(title: "Okay", style: UIAlertActionStyle.default, handler: { action in

    let myViewController:ViewController = self.storyboard!.instantiateViewController(withIdentifier: "ViewController") as! ViewController

    let appDelegate = UIApplication.shared.delegate as! AppDelegate
    let navigationController = UINavigationController.init(rootViewController: myViewController)
    appDelegate.window?.rootViewController = navigationController
    appDelegate.window?.makeKeyAndVisible()

    if (statement here == 1) {
        self.callAlert()
    }
})

myAlert.addAction(okaction)
self.present(myAlert, animated: true, completion: nil)

func callAlert() {
    let myAlert = UIAlertController(title: "Title", message: "title", preferredStyle: UIAlertControllerStyle.alert)
    myAlert.addAction(UIAlertAction(title: "Okay", style: UIAlertActionStyle.default, handler: nil))
    self.present(myAlert, animated: true, completion: nil)
}

---

尝试在

navigationController

上显示

AlertController

更改行

self.present(myAlert, animated: true, completion: nil)

与

navigationController.present(myAlert, animated: true, completion: nil)

---

假设我上面的代码在SecondViewController中，如果（statement==1）{}正在使用上面的代码使其工作。但是，如果我在它下面有另一个“if（statement==2）{}”，并且我想显示警报而不去rootViewController该怎么办呢。我的意思是它可以留在SecondViewController中吗？@AlotJai然后你需要写这两行

appDelegate.window？.rootViewController=navigationController appDelegate.window？.makeKeyAndVisible（）

inside

if（statement==1）{}