集成 Firebase 后，SDK 回调不触发

找到 packages/firebase_messaging/firebase_messaging/android/src/main/java/io/flutter/plugins/firebase/messaging/FlutterFirebaseMessagingBackgroundExecutor.java 类

修改代码如下：（来源参考：https://www.rongcloud.cn/?#seo）

```
if (shellArgs != null) {

Log.i(

TAG,

""Creating background FlutterEngine instance, with args: ""

+ Arrays.toString(shellArgs.toArray()));

   // 1. 修改此处如下

   // backgroundFlutterEngine =

   //     new FlutterEngine(

   //         ContextHolder.getApplicationContext(), shellArgs.toArray());

backgroundFlutterEngine =

new FlutterEngine(

ContextHolder.getApplicationContext(), shellArgs.toArray(), false);



} else {

Log.i(TAG, ""Creating background FlutterEngine instance."");

   // 2. 修改此处如下

   // backgroundFlutterEngine =

   //     new FlutterEngine(ContextHolder.getApplicationContext());

backgroundFlutterEngine =

new FlutterEngine(ContextHolder.getApplicationContext(), null, false);

}

```