iOS应用被VOIP唤醒，应用状态错误

Question

当应用收到消息时，我使用VOIP唤醒我的应用

func pushRegistry(_ registry: PKPushRegistry, didReceiveIncomingPushWith payload: PKPushPayload, for type: PKPushType, completion: @escaping () -> Void) {

}

然后将调用applicationDidBecomeActive

func applicationDidBecomeActive(_ application: UIApplication) {
}

我想检测应用是否被杀死，所以我添加以下代码，如

func applicationDidBecomeActive(_ application: UIApplication) {
    if application.applicationState == .background {
        // background
    } else if application.applicationState == .active {
        // active
    } else if application.applicationState == .inactive {
        // inactive
    }
}

但是applicationState始终返回.active，实际上该应用已被杀死。

我如何获得正确的身份？