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);
}
```