Swift Use of unresolved identifier 'UIApplicationStateInactive'

问题

In my Swift code to handle push notification I have this line:

if ( application.applicationState == UIApplicationStateInactive  || application.applicationState == UIApplicationStateBackground) {
}

Which cause the compilation error: Use of unresolved identifier 'UIApplicationStateInactive'

Am I missing some import files?

Thanks

回答1:

Currently your are using the identifiers for Objective-C. You need to use the identifier for swift:

UIApplicationState.Inactive // equals UIApplicationStateInactive
UIApplicationState.Background // equals UIApplicationStateBackground

Apple documentation for:

• Swift
• Objective-C

You can check the documentation for both languages in the Apple Documentation and choose the language in the top right corner.

来源：https://stackoverflow.com/questions/30363787/swift-use-of-unresolved-identifier-uiapplicationstateinactive