AppLifeCycleState.detached 未被调用

Question

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() {
    return _MyHomePageState();
  }
}

class _MyHomePageState extends State<MyHomePage> with WidgetsBindingObserver {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    print(state);
  }

  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () async {
        //do something here before pop
        return true;
      },
      child: Scaffold(
        body: Container(),
      ),
    );
  }
}

我的应用程序在上面。我正在尝试使用概览按钮并通过滑动关闭应用程序来检测我的应用程序何时在 Android 上被终止。问题是 AppLifeCycleState.detached 永远不会传递给我的回调。如果我通过按根上的后退按钮关闭应用程序，则会打印它。如果我通过从概览按钮滑动来杀死它，则回调不存在。我本质上是想获取本机 android 的 onDestroy() 调用。

这是我得到的日志：

D/SurfaceView(24406): windowStopped(true) false io.flutter.embedding.android.FlutterSurfaceView{d98238 V.E...... ........ 0,0-1080,2154} of ViewRootImpl@185dd4c[MainActivity]
I/flutter (24406): AppLifecycleState.paused
Lost connection to device.

预期日志：

D/SurfaceView(25394): windowStopped(true) false io.flutter.embedding.android.FlutterSurfaceView{2d5a56d V.E...... ........ 0,0-1080,2154} of ViewRootImpl@28f4397[MainActivity]
I/flutter (25394): AppLifecycleState.paused
I/flutter (25394): AppLifecycleState.detached
Lost connection to device.

Answer 1

显然，这是一个持续存在的颤振错误。https://github.com/flutter/flutter/issues/57594