Detect if the application in background or foreground in swift
IosIphoneSwiftSwift3LifecycleIos Problem Overview
is there any way to know the state of my application if it is in background mode or in foreground . Thanks
Ios Solutions
Solution 1 - Ios
[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 - Ios
Swift 3
let state: UIApplicationState = UIApplication.shared.applicationState
if state == .background {
// background
}
else if state == .active {
// foreground
}
Solution 3 - Ios
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 - Ios
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 - Ios
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
}
Solution 6 - Ios
you can add a boolean when the application enter in background or enter in foreground. You have this information by using the App delegate.
According the Apple documentation, maybe you can also use the mainWindow property of your Application or the active status property of the app.
NSApplication documentation > Discussion The value in this property is nil when the app’s storyboard or nib file has not yet finished loading. It might also be nil when the app is inactive or hidden.