Present UIAlertController from AppDelegate

Question

I'm trying to present a UIAlertController from the AppDelegate in my iOS app. Below is the alert and the present method.

UIAlertController *alert = [UIAlertController alertControllerWithTitle:cTitle message:cMessage preferredStyle:UIAlertControllerStyleAlert];

//Configure alert and actions

[self.window.rootViewController presentViewController:alert animated:TRUE completion:nil];

However, when I try to present the alert, it doesn't appear and I get the following alert in the console.

Warning: Attempt to present <UIAlertController: 0x145f5d60> on <UINavigationController: 0x146590f0> whose view is not in the window hierarchy!

What is causing the error and how do I fix it?

Trying to present right as the app is launching I'm guessing? — Acey, Nov 16 '14 at 00:33
Can you try this link for usefull Link: [ alertViewController](http://stackoverflow.com/a/37029075/2442762) — joel prithivi, May 04 '16 at 13:25

score 32 · Answer 1 · edited Jun 12 '20 at 06:39

32

You can use this code as well if you want to launch it from didFinishLaunchingWithOptions.Hope this helps.

dispatch_async(dispatch_get_main_queue(), {
              let importantAlert: UIAlertController = UIAlertController(title: "Action Sheet", message: "Hello I was presented from appdelegate ;)", preferredStyle: .ActionSheet)
            self.window?.rootViewController?.presentViewController(importantAlert, animated: true, completion: nil)
        })

And up-to-date:

DispatchQueue.main.async {
    let alert = UIAlertController(title: "Hello!", message: "Greetings from AppDelegate.", preferredStyle: .alert)
    self.window?.rootViewController?.present(alert, animated: true, completion: nil)
}

edited Jun 12 '20 at 06:39

Johan

2,472
1
23
25

answered Jul 23 '15 at 14:15

Aditya Gaonkar

660
6
13

Hi @AdiQuadCore, your is useful only in swift application. In objC, the `UIAlertController` needs a pointer to the current `UIViewController`. – Zeb Sep 16 '15 at 12:22
1

This worked for me in ObjC in didFinishLaunchingWithOptions – Seoras Oct 06 '16 at 05:04

score 20 · Answer 2 · answered Mar 03 '16 at 07:13

try this code..

-(void)application:(UIApplication *)application               didReceiveLocalNotification:(UILocalNotification *)notification
{
 NSLog(@"rakshapettu");
 UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"AlertView" message:@"I am an AlertView" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault
                                                      handler:^(UIAlertAction * action) {
                                                          [alert dismissViewControllerAnimated:YES completion:nil];
                                                      }];
[alert addAction:defaultAction];
UIWindow *alertWindow = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
alertWindow.rootViewController = [[UIViewController alloc] init];
alertWindow.windowLevel = UIWindowLevelAlert + 1;
[alertWindow makeKeyAndVisible];
[alertWindow.rootViewController presentViewController:alert animated:YES completion:nil]; 
}

How is the `UIWindow` deallocated? – meaning-matters Jul 10 '18 at 20:18 — meaning-matters, Jul 10 '18 at 20:18

score 13 · Answer 3 · edited Oct 18 '15 at 10:08

13

It's better to use something like:

var hostVC = self.window?.rootViewController

while let next = hostVC?.presentedViewController {
    hostVC = next
}

hostVC?.presentViewController(alertController, animated: true, completion: nil)

Previous answers won't work if you are already presenting modal view controller.

edited Oct 18 '15 at 10:08

John Topley

113,588
46
195
237

answered Oct 14 '15 at 15:00

Mikhail Mkl

139
1
2

Perfect answer and a really good method to handle modally presented view controllers! Thanks! – NerdyTherapist Nov 08 '16 at 11:34

score 5 · Answer 4 · answered Nov 16 '14 at 00:48

5

you call it before the window is up and the navigationController is actually shown:

"Warning: Attempt to present on whose view is not in the window hierarchy!"

likely you do so in applicationDidFinishLaunching?

EITHER wait .. like do it when the view really appears

OR

one 'hack' would be to force the view and window up yourself:

[self.window addSubview:self.rootViewController.view];
[self.window makeKeyAndVisible];

answered Nov 16 '14 at 00:48

Daij-Djan

49,552
17
113
135

If you aren't not *creating* a new Window, do you still have to do `makeKeyAndVisible`? For window that comes with AppDelegate, doesn't that happen by default?! – mfaani Dec 26 '16 at 14:48
In General: yes BUT It happens too late for the op's question – Daij-Djan Dec 26 '16 at 19:41
I'm confused. what do you mean too late? Is your code correct or not? – mfaani Dec 26 '16 at 20:34
Mine is correct for the given question :) makeKeyAndVisible is needed here – Daij-Djan Dec 26 '16 at 21:06

score 3 · Answer 5 · answered May 28 '16 at 02:08

I was trying the same but does not work because after change of viewcontroller still returned the initial viewcontroller and throw the error whose view is not in the window hierarchy!. Finally, I found the solution to this problem:

UIApplication.sharedApplication().keyWindow?.rootViewController?.presentViewController(alertController, animated: true, completion: nil)

But I have to force view controllers to update de keyWindow with this:

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated)
    UIApplication.sharedApplication().keyWindow!.rootViewController = self
    UIApplication.sharedApplication().keyWindow!.makeKeyAndVisible()
}

You should not do that, really. – Rafael Nobre Feb 28 '17 at 11:01 — Rafael Nobre, Feb 28 '17 at 11:01

score 1 · Answer 6 · answered Apr 21 '15 at 11:43

1

You can try calling it in viewDidAppear instead of viewDidLoad. I had a similar error and that fixed it.

answered Apr 21 '15 at 11:43

kakubei

5,321
4
44
66

Alvin George · Answer 7 · 2016-04-27T07:38:28.787

Using Alert Controller:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
dispatch_async(dispatch_get_main_queue(), {

    //INTERNET NOT AVAILABLE ALERT
    var internetUnavailableAlertController = UIAlertController (title: "Network Unavailable", message: "Please check your internet connection settings and turn on Network Connection", preferredStyle: .Alert)

    var settingsAction = UIAlertAction(title: "Settings", style: .Default) { (_) -> Void in
        let settingsUrl = NSURL(string: UIApplicationOpenSettingsURLString)
        if let url = settingsUrl {
            UIApplication.sharedApplication().openURL(url)
        }
    }
    var cancelAction = UIAlertAction(title: "Okay", style: .Default, handler: nil)
    internetUnavailableAlertController .addAction(settingsAction)
    internetUnavailableAlertController .addAction(cancelAction)
    self.window?.rootViewController!.presentViewController(internetUnavailableAlertController , animated: true, completion: nil)
    })

Using AlertView:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    dispatch_async(dispatch_get_main_queue(), {

        //INTERNET NOT AVAILABLE ALERTVIEW

        let internetUnavailableAlert =  UIAlertView(title: "Network Unavailable", message: "Please check your internet connection settings and turn on Network Connection", delegate: self, cancelButtonTitle: "Okay")
        internetUnavailableAlert.show()
        })

  return true
 }
}

UIAlertView is now deprecated. – Colin Basnett Nov 29 '16 at 00:21 — Colin Basnett, Nov 29 '16 at 00:21

Present UIAlertController from AppDelegate

7 Answers7

Linked

Related