Detect if the application in background or foreground in swift

Question

is there any way to know the state of my application if it is in background mode or in foreground . Thanks

Solution 1

[UIApplication sharedApplication].applicationState will return current state of applications such as:

• UIApplicationStateActive
• UIApplicationStateInactive
• UIApplicationStateBackground

or if you want to access via notification see UIApplicationDidBecomeActiveNotification

Swift 3+

let state = UIApplication.shared.applicationState
if state == .background || state == .inactive {
    // background
} else if state == .active {
    // foreground
}

switch UIApplication.shared.applicationState {
    case .background, .inactive:
        // background
    case .active:
        // foreground
    default:
        break
}

Objective C

UIApplicationState state = [[UIApplication sharedApplication] applicationState];
if (state == UIApplicationStateBackground || state == UIApplicationStateInactive) {
    // background
} else if (state == UIApplicationStateActive) {
    // foreground
}

Solution 2

Swift 3

  let state: UIApplicationState = UIApplication.shared.applicationState

            if state == .background {

                // background
            }
            else if state == .active {

                // foreground
            }

Solution 3

Swift 4

let state = UIApplication.shared.applicationState
        if state == .background {
            print("App in Background")
        }else if state == .active {
            print("App in Foreground or Active")
        }

Solution 4

Use these observers in viewDidload of your UIViewController:

let nc = NotificationCenter.default
nc.addObserver(self, selector: #selector(appMovedToBackground), name: UIApplication.didEnterBackgroundNotification, object: nil)
nc.addObserver(self, selector: #selector(appMovedToForeground), name: UIApplication.willEnterForegroundNotification, object: nil)

and methods:

@objc func appMovedToBackground() {    
}

@objc func appMovedToForeground() {
}

Solution 5

If somebody wants it in swift 3.0

switch application.applicationState {
    case .active:
        //app is currently active, can update badges count here
        break
    case .inactive:
        //app is transitioning from background to foreground (user taps notification), do what you need when user taps here
        break
    case .background:
        //app is in background, if content-available key of your notification is set to 1, poll to your backend to retrieve data and update your interface here
        break
    default:
        break
    }

for swift 4

switch UIApplication.shared.applicationState {
case .active:
    //app is currently active, can update badges count here
    break
case .inactive:
    //app is transitioning from background to foreground (user taps notification), do what you need when user taps here
    break
case .background:
    //app is in background, if content-available key of your notification is set to 1, poll to your backend to retrieve data and update your interface here
    break
default:
    break
}

View more solutions

Comments

[Anbu.Karthik]

@MohammedAboelwafa - I modifed check teh updated answer

[Mohammed Aboelwafa]

Thanks @Anbu.Karthik

[Saleem Khan]

can you share the complete code. Where we will test this function?

[dimohamdy]

@SaleemKhan in any function you want to use it some time you want to know app in foreground to take photo using camera or not

[Saleem Khan]

I want to check if the app is running in the background and user click on the notification message then log out the app. So I want to you please confirm to me the app is the view from the background or not?

[Amir Shabani]

Actually there are differences between background in our mind and ios's thoughts. see this link

[bibscy]

@MohammedAboelwafa My app has a SegmentedControl on top of table view. If the app is in foreground, then goes back in background(user taps home button) and he taps again on the app after 2 days. Where should I check for the state of the app, ViewDidLoad, was initialized 2 days ago, viewWillAppear will not be called. So how do I get to check?

[Anbu.Karthik]

@bibscy- based on your ?, the apple delegate method UIApplicationDidBecomeActive will call

[user924]

it returns inactive even if app visible

[user924]

it returns inactive even if app visible (in viewDidLoad)

[Anbu.Karthik]

@user924 - is this possible to attach the video