未解析的类'MyFirebaseMessagingService'

Question

我正在关注Android上设置Firebase Cloud Messaging客户端应用程序的教程，该应用程序涉及将<service>组件添加到AndroidManifest.xml。

<service android:name=".java.MyFirebaseMessagingService">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

但是，我得到了Unresolved class MyFirebaseMessagingService。我到底从哪里导入该课程？

注意：我正在Kotlin写作

Answer 1

在您提供的相同链接上，提到您需要在项目中添加服务类并在AndroidManifest.xml中声明它：

<service android:name=".java.MyFirebaseMessagingService">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

基本上这些是您需要遵循的步骤：

1. 在您的软件包内保存Java类，创建一个名为MyFirebaseMessagingService的类（您可以选择任何名称）
2. 如上图所示，在AndroidManifest.xml中声明。

3. 您在上面步骤1中定义的此类将扩展FirebaseMessagingService，因此它将具有一种称为onMessageReceived的方法，您必须覆盖，如下所示：

      @Override
       public void onMessageReceived(RemoteMessage remoteMessage) {
           // ...
       // TODO(developer): Handle FCM messages here.
       Log.d(TAG, "From: " + remoteMessage.getFrom());
       // Check if message contains a data payload.
       if (remoteMessage.getData().size() > 0) {
           Log.d(TAG, "Message data payload: " + remoteMessage.getData());
           if (/* Check if data needs to be processed by long running job */ true) {
               // For long-running tasks (10 seconds or more) use Firebase Job Dispatcher.
               scheduleJob();
           } else {
               // Handle message within 10 seconds
               handleNow();
           }
       }
       // Check if message contains a notification payload.
       if (remoteMessage.getNotification() != null) {
           Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());
       }
       // 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.
   }
   

如果您是在Kotlin中编写代码，则需要将您的类命名为MyFireBaseMessagingService.kt，然后创建一个类并放在代码下方。该链接本身也提到了这一点。

override fun onMessageReceived(remoteMessage: RemoteMessage?) {
// ...
// TODO(developer): Handle FCM messages here.
Log.d(TAG, "From: ${remoteMessage?.from}")
// Check if message contains a data payload.
remoteMessage?.data?.isNotEmpty()?.let {
    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 Firebase Job Dispatcher.
        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.
}