有个坏消息。
Google 更改版本“com.google.firebase:firebase-messaging:11.6.0”中的 Firebase 源代码。
handelIntent 现在是“公共最终无效方法”。这意味着我们不能覆盖它。
如果要使用该解决方案，请将版本更改为“com.google.firebase:firebase-messaging:11.4.2”
试试我的方法。项目构建版本为Android 6.0以上（api level 23）可以完美运行，我已经试过了。
有比official site tutorial更好的方法
官网说app在后台时系统会创建通知。所以你不能通过覆盖“onMessageReceived()”来处理它。因为“onMessageReceived()”仅在应用程序处于前台时触发。
但事实并非如此。实际上通知（当应用在后台时）是由 Firebase 库创建的。
在我跟踪了 firebase 库代码之后。我找到了更好的方法。
第 1 步：在 FirebaseMessagingService 中覆盖“handleIntent()”而不是“onMessageReceived()”
为什么：
因为该方法将触发应用程序在前台或后台。所以我们可以在这两种情况下处理 FCM 消息并创建我们的自定义通知。
@Override
public void handleIntent(Intent intent) {
Log.d( "FCM", "handleIntent ");
}
第 2 步。从 FCM 解析消息
如何：
如果您不知道您设置的消息格式。打印出来并尝试解析它。
Here is the basic illustration
Bundle bundle = intent.getExtras();
if (bundle != null) {
for (String key : bundle.keySet()) {
Object value = bundle.get(key);
Log.d("FCM", "Key: " + key + " Value: " + value);
}
}
第 2 步：删除应用在后台时由 Firebase 库创建的通知
为什么：
我们可以创建我们的自定义通知。但是Firebase库创建的通知仍然存在（实际上它是由“”super.handleIntent（intent）“”创建的。下面有详细说明。）。然后我们会有两个通知。那是相当奇怪的。所以我们必须删除 Firebase 库创建的通知
如何（项目构建级别为 Android 6.0 以上）：
识别我们要删除的通知并获取信息。并使用“notificationManager.cancel()”删除它们。
private void removeFirebaseOrigianlNotificaitons() {
//check notificationManager is available
NotificationManager notificationManager =
(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
if (notificationManager == null )
return;
//check api level for getActiveNotifications()
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
//if your Build version is less than android 6.0
//we can remove all notifications instead.
//notificationManager.cancelAll();
return;
}
//check there are notifications
StatusBarNotification[] activeNotifications =
notificationManager.getActiveNotifications();
if (activeNotifications == null)
return;
//remove all notification created by library(super.handleIntent(intent))
for (StatusBarNotification tmp : activeNotifications) {
Log.d("FCM StatusBarNotification",
"StatusBarNotification tag/id: " + tmp.getTag() + " / " + tmp.getId());
String tag = tmp.getTag();
int id = tmp.getId();
//trace the library source code, follow the rule to remove it.
if (tag != null && tag.contains("FCM-Notification"))
notificationManager.cancel(tag, id);
}
}
我的完整示例代码：
public class MyFirebaseMessagingService extends FirebaseMessagingService {
private static int notificationCount=0;
@Override
public void handleIntent(Intent intent) {
//add a log, and you'll see the method will be triggered all the time (both foreground and background).
Log.d( "FCM", "handleIntent");
//if you don't know the format of your FCM message,
//just print it out, and you'll know how to parse it
Bundle bundle = intent.getExtras();
if (bundle != null) {
for (String key : bundle.keySet()) {
Object value = bundle.get(key);
Log.d("FCM", "Key: " + key + " Value: " + value);
}
}
//the background notification is created by super method
//but you can't remove the super method.
//the super method do other things, not just creating the notification
super.handleIntent(intent);
//remove the Notificaitons
removeFirebaseOrigianlNotificaitons();
if (bundle ==null)
return;
//pares the message
CloudMsg cloudMsg = parseCloudMsg(bundle);
//if you want take the data to Activity, set it
Bundle myBundle = new Bundle();
myBundle.putSerializable(TYPE_FCM_PLATFORM, cloudMsg);
Intent myIntent = new Intent(this, NotificationActivity.class);
myIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
myIntent.putExtras(myBundle);
PendingIntent pendingIntent = PendingIntent.getActivity(this, notificationCount, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
//set the Notification
NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
.setSmallIcon(R.mipmap.icon)
.setContentTitle(cloudMsg.getTitle())
.setContentText(cloudMsg.getMessage())
.setAutoCancel(true)
.setContentIntent(pendingIntent);
NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(notificationCount++, notificationBuilder.build());
}
/**
* parse the message which is from FCM
* @param bundle
*/
private CloudMsg parseCloudMsg(Bundle bundle) {
String title = null, msg=null;
//if the message is sent from Firebase platform, the key will be that
msg = (String) bundle.get("gcm.notification.body");
if(bundle.containsKey("gcm.notification.title"))
title = (String) bundle.get("gcm.notification.title");
//parse your custom message
String testValue=null;
testValue = (String) bundle.get("testKey");
//package them into a object(CloudMsg is your own structure), it is easy to send to Activity.
CloudMsg cloudMsg = new CloudMsg(title, msg, testValue);
return cloudMsg;
}
/**
* remove the notification created by "super.handleIntent(intent)"
*/
private void removeFirebaseOrigianlNotificaitons() {
//check notificationManager is available
NotificationManager notificationManager =
(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
if (notificationManager == null )
return;
//check api level for getActiveNotifications()
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
//if your Build version is less than android 6.0
//we can remove all notifications instead.
//notificationManager.cancelAll();
return;
}
//check there are notifications
StatusBarNotification[] activeNotifications =
notificationManager.getActiveNotifications();
if (activeNotifications == null)
return;
//remove all notification created by library(super.handleIntent(intent))
for (StatusBarNotification tmp : activeNotifications) {
Log.d("FCM StatusBarNotification",
"tag/id: " + tmp.getTag() + " / " + tmp.getId());
String tag = tmp.getTag();
int id = tmp.getId();
//trace the library source code, follow the rule to remove it.
if (tag != null && tag.contains("FCM-Notification"))
notificationManager.cancel(tag, id);
}
}
}