Android端 Fragment 包含的 Flutter 页面 首次启动 没有初始化 白屏或黑屏

Android端 Fragment 包含的 Flutter 页面 首次启动 没有初始化 白屏或黑屏

App是登录后展示4个Tab。4个Tab是原生写的 tab里面嵌的是 Fragment , Fragment里面放的Flutter页面

mHomeFragment = new CunwFlutterFragment
.CachedEngineFragmentBuilder(CunwFlutterFragment.class)
.url("/home")
.build();

mClasssFragment = new ClasssFlutterFragment
.CachedEngineFragmentBuilder(ClasssFlutterFragment.class)
.url("/classs")
.build();

升级 flutter_boost 从 v3.0-preview.5. 到 v3.0-null-safety-preview.13 支持空安全版本后
Android端出现此问题
IOS端没有问题

日志
2021-11-25 10:36:30.121 29743-29999/cn.com.cunw.teacheraide I/flutter: ══╡ EXCEPTION CAUGHT BY SCHEDULER LIBRARY ╞══════════════════════
The following _CastError was thrown during a scheduler callback:
Null check operator used on a null value

When the exception was thrown, this was the stack:
#0 BoostChannel.addEventListener (package:flutter_boost/boost_channel.dart:42:21)
#1 FlutterBoostAppState._addAppLifecycleStateEventListener (package:flutter_boost/flutter_boost_app.dart:125:10)
#2 FlutterBoostAppState.initState. (package:flutter_boost/flutter_boost_app.dart:102:7)
#3 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1143:15)
#4 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1088:9)
#5 SchedulerBinding.scheduleWarmUpFrame. (package:flutter/src/scheduler/binding.dart:863:7)
(elided 11 frames from class _RawReceivePortImpl, class _Timer, dart:async, and dart:async-patch)
════════

overlayKey.currentContext 为null

Start by reproducing the first launch on Android with Flutter pages embedded in native Fragments after upgrading flutter_boost, then inspect the reported stack frames in package:flutter_boost/boost_channel.dart and package:flutter_boost/flutter_boost_app.dart. Use the overlayKey.currentContext null log to trace initialization timing. Done means the first launch initializes normally without a white or black screen or the reported null-check exception.

Written by the indexing model from the issue text.