当应用处于后台时启动后台服务

Question

当我们收到通知时，如何使用后台服务启动警报？当我的应用程序处于活动状态时，后台服务很容易启动，但当应用程序处于后台时，后台服务器就无法运行。

Answer 1

1。为什么会发生这种情况

FCM(Firebase Cloud Messaging(中有两种类型的消息：

显示消息：只有当您的应用程序处于前台时，这些消息才会触发onMessageReceived((回调

数据消息：这些消息触发onMessageReceived((回调，即使您的应用程序处于前台/后台/已终止

override fun onMessageReceived(remoteMessage: RemoteMessage) {
// ...
// TODO(developer): Handle FCM messages here.
// Not getting messages here? See why this may be:
Log.d(TAG, "From: ${remoteMessage.from}")
// Check if message contains a data payload.
if (remoteMessage.data.isNotEmpty()) {
Log.d(TAG, "Message data payload: ${remoteMessage.data}")
if (/* Check if data needs to be processed by long running job */ true) {
// For long-running tasks (10 seconds or more) use WorkManager.
scheduleJob()
} else {
// Handle message within 10 seconds
handleNow()
}
}
// Check if message contains a notification payload.
remoteMessage.notification?.let {
Log.d(TAG, "Message Notification Body: ${it.body}")
}
// Also if you intend on generating your own notifications as a result of a received FCM
// message, here is where that should be initiated. See sendNotification method below.
}