ios - UIAlert 不适用于 NSNotification

Question

我将 Reachability.swift 文件放在我的应用程序中，当互联网可达性发生变化时，我想提醒用户互联网连接不可用。

这是我的代码。

import UIKit
import Parse

class ViewController: UIViewController {
var reachability : Reachability?
var myAlert = UIAlertController()

@IBOutlet weak var label: UILabel!
@IBOutlet weak var textField: UITextField!
override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(true)

    do {
        let reachability = try Reachability.reachabilityForInternetConnection()
        self.reachability = reachability
    } catch ReachabilityError.FailedToCreateWithAddress(let address) {

    }
    catch {}


NSNotificationCenter.defaultCenter().addObserver(self, selector: "HeyUserInternetDoesntWork", name: ReachabilityChangedNotification, object: nil)

     }

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

@IBAction func saveButtonTapped(sender: AnyObject) {

    let save = PFObject(className: "Practice")
    save["text"] = textField.text
    save.saveInBackgroundWithBlock { (success: Bool, error: NSError?) -> Void in
        print("Object has been saved.")
    }

}


   dynamic func HeyUserInternetDoesntWork() {


    if reachability!.isReachable() {


    } else {


         myAlert = UIAlertController(title: "No internet", message: "no good", preferredStyle: UIAlertControllerStyle.Alert)
        let okAction = UIAlertAction(title: "Ok", style: UIAlertActionStyle.Default, handler: nil)
        myAlert.addAction(okAction)        }
}

这是行不通的，我得到一个错误

Attempting to load the view of a view controller while it is deallocating is not allowed and may result in undefined behaviour

我不明白这是什么意思。如果我输入 print("unreachable") 将正常工作的代码。

我的问题

这个错误是什么意思？

我怎样才能让我的警报起作用？

如果有其他方式让用户知道 Internet 连接情况，

请告诉我。

Answer 1

尝试在警报下添加这一行(self.presentViewController(myAlert, animated: true, completion: nil))