Unsupported operation: Platform._operatingSystem

问题

My flutter code isn't running on web.

I found that "bool kisweb" can be used to detect the platform. But my code is failing at "FirebaseAuth.instance". Does this mean I can't use Firebaseauth on web as it might be depending on dart:io?

Launching lib\main.dart on Chrome in debug mode... Debug service listening on ws://127.0.0.1:54007/NghsYaNRLKE= compiled for web ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════ The following UnsupportedError was thrown building MultiProvider: Unsupported operation: Platform._operatingSystem The relevant error-causing widget was: MultiProvider org-dartlang-app:///packages/My_App/main.dart:30:10 When the exception was thrown, this was the stack: package:build_web_compilers/src/dev_compiler/dart_sdk.js 3996:11
throw_ package:build_web_compilers/src/dev_compiler/dart_sdk.js 57810:17 _operatingSystem package:build_web_compilers/src/dev_compiler/dart_sdk.js 57859:27 get operatingSystem package:build_web_compilers/src/dev_compiler/dart_sdk.js 57772:27 get _operatingSystem package:build_web_compilers/src/dev_compiler/dart_sdk.js 5020:17 get package:build_web_compilers/src/dev_compiler/dart_sdk.js 57796:26 get isIOS package:build_web_compilers/src/dev_compiler/dart_sdk.js 5020:17 get package:firebase_core/src%5Cfirebase_app.dart 15:16
get defaultAppName package:build_web_compilers/src/dev_compiler/dart_sdk.js 5020:17 get package:firebase_core/src%5Cfirebase_app.dart 51:57 get instance package:build_web_compilers/src/dev_compiler/dart_sdk.js 5020:17 get package:firebase_auth/src%5Cfirebase_auth.dart 25:67
get instance package:build_web_compilers/src/dev_compiler/dart_sdk.js 5020:17 get internalCallback ════════════════════════════════════════════════════════════════════════════════════════════════════ Exited

Please help me resolve this issue.

回答1:

No, the FlutterFire group of plugins is in no way supported on Flutter Web. They rely on platform-specific APIs and are currently only implemented for Android and iOS.

回答2:

You can use a try-catch block to prevent the exception from breaking the flow:

bool kisweb;
try{
    if(Platform.isAndroid||Platform.isIOS) {
        kisweb=false;
    } else {
        kisweb=true;
    }
} catch(e){
    kisweb=true;
}

回答3:

For me, shifting to dev channel worked using flutter channel dev

Web support is now available for most of the firebase plugins.

回答4:

I have spent last 4 hours researching this issue. All that was already mentioned is correct. However, I'm so happy I found a working solution for web, too: universal_io package.

Just remember not to use the 1.0.1 version cause v1.0.1 and other versions don't detect iOS correctly. I was able to go away with it by just downgrading to 0.2.0 version. By the time you read this post it may have been fixed, check out the issue status here:https://github.com/dint-dev/universal_io/issues/8

IMPLEMENTATION (super simple)

import 'package:universal_io/io.dart';

then just use Platform.operatingSystem e.g.

print('OS: ${Platform.operatingSystem}');

来源：https://stackoverflow.com/questions/58459483/unsupported-operation-platform-operatingsystem

标签

Flutter

flutter-web