exception - Flutter 捕获所有未处理的异常

Question

我试图在 Flutter 应用程序中捕获所有未处理的异常，以便将其发送给崩溃报告者。有instructions on how to do this in the Flutter docs .我遵循了这些，并在我的应用程序中添加了两段代码以捕获异常:
通过包装 runApp 来捕获 Dart 错误在 runZoned :

runZoned<Future<void>>(
  () async {
    runApp(MyApp());
  },
  onError: (dynamic error, StackTrace stackTrace) {
    print("=================== CAUGHT DART ERROR");
    // Send report
  },
);

通过设置 FlutterError.onError 来捕捉抖动错误:

FlutterError.onError = (FlutterErrorDetails details) {
  print("=================== CAUGHT FLUTTER ERROR");
  // Send report
};

但是，当我在运行时通过从按钮抛出异常进行测试时:

throw Exception("Just testing");

控制台中出现异常:

════════ Exception Caught By gesture═══════════════════════════════════════════════════════════════The following _Exception was thrown while handling a gesture: Exception:Just testing When the exception wasthrown, this was the stack:

... etc

但是我看不到我的打印语句的迹象(CAUGHT DART ERROR 或 CAUGHT FLUTTER ERROR)，并且在这些行上设置断点似乎永远不会命中，所以我认为我的异常处理代码没有捕捉到它。我错过了什么吗？
这是一个最小的可重现示例(单击按钮，该按钮会引发异常，但未按预期捕获):

import 'dart:async';
import 'package:flutter/material.dart';

void main() =>
  runZoned<Future<void>>(
    () async {
      runApp(MyApp());
    },
    onError: (dynamic error, StackTrace stackTrace) {
      print("=================== CAUGHT DART ERROR");
      // Send report
      // NEVER REACHES HERE - WHY?
    },
  );

class MyApp extends StatefulWidget {
  // This widget is the root of your application.
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {

  @override
  void initState() {
    super.initState();

    // This captures errors reported by the FLUTTER framework.
    FlutterError.onError = (FlutterErrorDetails details) {
      print("=================== CAUGHT FLUTTER ERROR");
      // Send report
      // NEVER REACHES HERE - WHY?
    };
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: SafeArea(
          child: RaisedButton(
            child: Text("Throw exception"),
            onPressed: () {
              throw Exception("This is a test exception");
            },
          ),
        ),
      ),
    );
  }
}

Answer 1

好吧，我想通了是怎么回事。查看了一些相关的 Flutter 问题:

flutter tool is too aggressive about catching exceptions

Make hot mode a little less aggressive about catching errors

Break on "unhandled" exceptions when a debugger is attached

看起来在 Debug模式下，flutter 框架捕获了很多异常，打印到控制台(有时在 UI 本身中以红色和黄色显示)，但不会重新抛出 - 所以它们被有效地吞下，并且有您自己的代码无法捕获它们。但是，当您在 Release模式下部署时，这不会发生。因此，我的最小可重现示例在以 Release模式构建时确实会捕获异常。