ios - 快速检测应用程序是在后台还是在前台

Question

有什么方法可以知道我的应用程序处于后台模式还是前台模式。谢谢

Answer 1

[UIApplication sharedApplication].applicationState 将返回应用程序的当前状态，例如:

• UIApplicationStateActive
• UIApplicationStateInactive
• UIApplicationStateBackground

或者如果您想通过通知访问，请参阅 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
}