import 'fléchette: io'; pas de support sur l'application Web

lorsque j'utilise la bibliothèque dart: io sur le Web Flutter, un avertissement apparaît lors du débogage. comme ça

[AVERTISSEMENT] build_web_compilers: entrypoint sur web / main.dart: Ignorer la compilation de retgoo_internal | web / main.dart avec ddc car certains de ses les bibliothèques transitives ont des dépendances sdk qui ne sont pas prises en charge sur ce plateforme:

retgoo_internal | lib / protocol / http_aiframework.dart

mais quand j'utilise import 'package: flutter_web / io.dart'; il y a un code d'erreur, dans le code .transform voici le http_aiframework.dart code

import 'dart:async';
import 'dart:convert';
import 'dart:io';
//import 'package:flutter_web/io.dart';

import '../main.dart';

typedef HttpProgressListener(int totalBytes, int receivedBytes, bool done);

class Http {
  static String baseURL;

  static bool loadAccessToken() {
    return accessToken != null;
  }

  static bool setAccessToken(String token) {
    accessToken = token;
    return accessToken != null;
  }

  static bool removeAccessToken() {
    accessToken = null;
    return accessToken == null;
  }

  static _processHeader(
      {HttpClientRequest request, Map<String, dynamic> headers}) {
    if (headers != null) {
      headers.forEach((key, value) {
        request.headers.add(key, value);
      });
    }

    if (accessToken != null) {
      request.headers.set("Authorization", "Bearer " + accessToken);
    }
  }

  static _processResponse(
      {HttpClientResponse response,
      HttpProgressListener progressListener}) async {
    final int totalBytes = response.contentLength;
    int receivedBytes = 0;

    String body = await response
        .transform( //this is the error code when I use import 'package: flutter_web / io.dart';
          StreamTransformer.fromHandlers(
            handleData: (data, sink) {
              sink.add(data);

              if (progressListener != null) {
                receivedBytes += data.length;
                progressListener(totalBytes, receivedBytes, false);
              }
            },
            handleDone: (sink) {
              sink.close();
              if (progressListener != null) {
                progressListener(totalBytes, receivedBytes, true);
              }
            },
          ),
        )
        .map((v) => utf8.decoder.convert(v))
        .join();

    return body;
  }

  static getData({
    String baseURL,
    String endpoint,
    Map<String, dynamic> headers,
    HttpProgressListener downloadProgressListener,
    dynamic data,
  }) async {
    final client = HttpClient();
    client.userAgent = "AIFramework/";
    client.connectionTimeout = Duration(seconds: 30);

    HttpClientRequest request;
    String mBaseURL = baseURL ?? Http.baseURL;

    var uri = Uri.parse("$mBaseURL$endpoint");

    if (data == null) {
      request = await client.getUrl(uri);
    } else {
      request = await client.postUrl(uri);
    }

    _processHeader(
      request: request,
      headers: headers,
    );

    if (data != null) {
      String payload = json.encode(data);
      request.write(payload);
    }

    final response = await request.close();
    if (response.statusCode == 200) {
      return json.decode(
        await _processResponse(
          response: response,
          progressListener: downloadProgressListener,
        ),
      );
    }

    return null;
  }
}