Get Application's main window

Question

UIApplication has a method keyWindow, however if an alert view is showing then this returns the window of the alert view and not the main window of the application.

How can I get the app's main window?

take a look this question might Help's you :- http://stackoverflow.com/questions/7871241/is-a-mainwindow-xib-truly-needed-in-ios-application — Nitin Gohel, Jul 24 '13 at 17:53

score 59 · Answer 1 · edited Mar 24 '19 at 18:28

59

The UIApplicationDelegate usually has a reference to the "main window":

[[[UIApplication sharedApplication] delegate] window];

Furthermore, UIApplication has an array of windows [[UIApplication sharedApplication] windows].

See the UIApplication Class Reference.

edited Mar 24 '19 at 18:28

Cœur

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answered Jul 24 '13 at 17:43

Espresso

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This is optional for the delegate isn't it? I'm hoping for a more "concrete" way – Jonathan. Jul 24 '13 at 17:44
[[[UIApplication shareApplication] delegate] window] -- works fine. – Basem Saadawy Mar 07 '14 at 19:44

score 12 · Answer 2 · answered Jul 24 '13 at 17:47

12

I'm not 100% sure this works in every case but this should work:

UIWindow *mainWindow = [UIApplication sharedApplication].windows[0];

The windows are ordered back to front so the main window should always be at index 0.

answered Jul 24 '13 at 17:47

rmaddy

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You should call `[[[UIApplication sharedApplication] windows] firstObject]` to avoid an out of bounds exception if there are no windows (not like there would never be any windows, but it's a good habit to avoid those – michaellindahl Aug 15 '14 at 19:21
@michaellindahl even if 12 people agreed. I can't say it's a good habit 'to check something even if we don't know how it works. Even you wrote: "not like there would never be any windows". The best choice here is to write explicitly: "I'm sure there is a window index 0". It will lead you to a bounds exception. And it's Great! You can't win with a strategy as Michael suggested - it will lead to a mess with these necessary checkings. Who knows later if we need them. – Vlad Servitola Sep 19 '22 at 15:03

score 7 · Answer 3 · edited May 23 '17 at 12:18

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Swift 3.0 version of rmaddy's answer:

let window = UIApplication.shared.windows.first

I also should add that since iOS 8.0 UIAlertController has replaced UIAlertView and being a view controller you may no longer face the issue of new windows being created.

edited May 23 '17 at 12:18

Community

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answered Dec 27 '16 at 22:53

fpg1503

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score 3 · Answer 4 · answered Jul 24 '13 at 18:03

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UIApplication *application = [UIApplication sharedInstance];
NSarray *appWindows = [NSArray arrayWithArray:application.windows];
UIWindow *mainWindow = [appWindows objectAtIndex:0];

I am not sure but this might help.

answered Jul 24 '13 at 18:03

RKY

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score 3 · Answer 5 · answered Apr 29 '16 at 19:44

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In Swift:

UIApplication.sharedApplication().delegate?.window

answered Apr 29 '16 at 19:44

Glauco Neves

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score 0 · Answer 6 · answered May 20 '16 at 09:53

For me I was presenting a popViewController

self.presentViewController(popViewController, animated: true, completion: nil)

and then in the viewDidLoad() of this popViewController I was adding a subview, this causes the error in the console and a display bug. So I have to find another solution to make it work. Hope this helps.

score 0 · Answer 7 · answered Dec 27 '16 at 22:47

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Swift 3

    if let window = NSApplication.shared().windows.first {
        // you can now modify window attributes
    }

answered Dec 27 '16 at 22:47

Ted Lowery

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He said `UIApplication` not `NSApplication`, it's tagged as iOS – fpg1503 Dec 27 '16 at 22:51
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If I had a dollar for every time this has happened in reverse (people answering Cocoa questions with Cocoa Touch answers), I'd be a wealthy man. :) Cut Ted some slack. :) – Clifton Labrum Nov 10 '17 at 20:57

score -2 · Answer 8 · answered Mar 31 '17 at 11:20

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Swift 3

class func sharedInstance() -> AppDelegate{
        return UIApplication.shared.delegate as! AppDelegate
    }

answered Mar 31 '17 at 11:20

Ved Rauniyar

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Get Application's main window

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