android - 将 Firebase 通知的 MessageBody 显示为 Toast

Question

我在显示 Toast 消息时遇到运行时异常

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

当用户从应用中的任何位置收到推送通知时，我想将消息正文显示为 Toast 消息。

有什么帮助吗？

public class MyAppFirebaseMessagingService extends FirebaseMessagingService {

    private static final String TAG = "FCM Service";

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
              if (remoteMessage.getNotification() != null) {
            if (AppConfig.SYSTEM_WIDE_DEBUG) {
                Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());
            }

            sendNotification(remoteMessage.getNotification().getBody());
        }

    }

    private void sendNotification(String messageBody) {
        Toast.makeText(getApplicationContext(),messageBody,Toast.LENGTH_LONG).show();

        Intent intent = new Intent(this, HomeActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0 /* Request code */, intent, PendingIntent.FLAG_ONE_SHOT);

        Uri defaultSoundUri = Uri.parse("android.resource://" + getPackageName() + "/" + R.raw.pushnotify);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
                .setSmallIcon( R.mipmap.ic_launcher)
                .setContentTitle("My APP")
                .setContentText(messageBody)
                .setAutoCancel(true)
                .setSound(defaultSoundUri)
                .setContentIntent(pendingIntent);

        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        notificationManager.notify(0 /* ID of notification */, notificationBuilder.build());
    }
}

Answer 1

如果你想在 UI Thread 上显示 Toast.Run 是最好的方法；

例子:

Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
    public void run() {
        Toast.makeText(getApplicationContext(),Toast.LENGTH_SHORT).show();
    }
});

另一种方式:

if (Looper.myLooper() == null) {
    Looper.prepare();
    Toast.makeText(getApplicationContext(), "xxxxxxxxx", Toast.LENGTH_SHORT).show();
    Looper.loop();
}

因为源码中Toast使用了Handler，但是当前Thread没有初始化Looper。