Flutter 未處理的異常：SocketException：操作系統錯誤：連接被拒絕，errno = 111

Question

我正在嘗試獲取一個在 android studio 中制作的 flutter 應用程序，以連接到本地托管的 ac# api。 在 IIS Express 上運行 api 會提供一個 URL 為https://localhost:44364/api/trip ，我認為這與使用模擬器時 Android studio 中的http://10.0.2.2:44364/api有關。

我正在嘗試通過 API 從數據庫中檢索行程列表。 郵遞員工作正常。

我收到多個錯誤。 我試過模擬器，我也試過直接插入電話並將地址切換到我的IP地址。 我什至嘗試將 api 切換為在控制台而不是 IIS 中運行。 什么都行不通。

我確實嘗試通過模擬器瀏覽器訪問 api，但被告知該站點不安全，導致我認為這是一個證書問題。

Flutter 項目相當簡單，它處於起步階段，我仍在學習如何對其進行編程。

這是三個顫振文件，以及錯誤列表。

main.dart

import 'dart:convert';
import 'package:bike_client/API.dart';
import 'package:bike_client/models/Trip.dart';
import 'package:flutter/material.dart';

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

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

class MyHomePage extends StatefulWidget {
  @override
  createState() => new _MyHomePageState();
}

class _MyHomePageState extends State {
  var trips = new List<Trip>();

  _getTrips() {
    API.getTrips().then((response) {
      setState(() {
        Iterable list = json.decode(response.body);
        trips = list.map((model) => Trip.fromJson(model)).toList();
      });
    });
  }

  initState() {
    super.initState();
    _getTrips();
  }

  dispose() {
    super.dispose();
  }

  @override
  build(context) {
    return Scaffold(
        appBar: AppBar(
          title: Text("Trip List"),
        ),
        body: ListView.builder(
          itemCount: trips.length,
          itemBuilder: (context, index) {
            return ListTile(title: Text((trips[index].tripId).toString()));
          },
        ));
  }
}

API.dart

import 'dart:async';
import 'package:http/http.dart' as http;

//const baseUrl = "https://192.168.1.14:44364/api";
const baseUrl = "http://10.0.2.2:44364/api";

class API {
  static Future getTrips() {
    var url = baseUrl + "/trip/1";
    return http.get(url);
  }
}

飛鏢

class Trip {
  int tripId;
  int userId;

  Trip(int tripId, int userId) {
    this.tripId = tripId;
    this.userId = userId;
  }

  Trip.fromJson(Map json)
      : tripId = json['tripId'],
        userId = json['userId'];

  Map toJson() {
    return {'tripId': tripId, 'userId': userId};
  }
}

安慰

Launching lib\main.dart on AOSP on IA Emulator in debug mode...
Running Gradle task 'assembleDebug'...
E/flutter ( 7781): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: SocketException: OS Error: Connection refused, errno = 111, address = localhost, port = 38612
E/flutter ( 7781): #0      IOClient.send (package:http/src/io_client.dart:33:24)
E/flutter ( 7781): <asynchronous suspension>
E/flutter ( 7781): #1      BaseClient._sendUnstreamed (package:http/src/base_client.dart:176:38)
E/flutter ( 7781): #2      BaseClient.get (package:http/src/base_client.dart:35:7)
E/flutter ( 7781): #3      get.<anonymous closure> (package:http/http.dart:46:36)
E/flutter ( 7781): #4      _withClient (package:http/http.dart:166:20)
E/flutter ( 7781): #5      get (package:http/http.dart:46:5)
E/flutter ( 7781): #6      API.getTrips (package:bike_client/API.dart:9:12)
E/flutter ( 7781): #7      _MyHomePageState._getTrips (package:bike_client/main.dart:30:9)
E/flutter ( 7781): #8      _MyHomePageState.initState (package:bike_client/main.dart:40:5)
E/flutter ( 7781): #9      StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4355:58)
E/flutter ( 7781): #10     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #11     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #12     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #13     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #14     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #15     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #16     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #17     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #18     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #19     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #20     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #21     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #22     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #23     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #24     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #25     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #26     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #27     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #28     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #29     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #30     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #31     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4381:11)
E/flutter ( 7781): #32     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #33     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #34     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #35     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #36     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #37     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #38     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #39     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #40     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #41     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #42     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #43     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #44     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4381:11)
E/flutter ( 7781): #45     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #46     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #47     Element.updateChild (package:flutter/src/wid
E/flutter ( 7781): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: SocketException: OS Error: Connection refused, errno = 111, address = localhost, port = 38760
E/flutter ( 7781): #0      IOClient.send (package:http/src/io_client.dart:33:24)
E/flutter ( 7781): <asynchronous suspension>
E/flutter ( 7781): #1      BaseClient._sendUnstreamed (package:http/src/base_client.dart:176:38)
E/flutter ( 7781): #2      BaseClient.get (package:http/src/base_client.dart:35:7)
E/flutter ( 7781): #3      get.<anonymous closure> (package:http/http.dart:46:36)
E/flutter ( 7781): #4      _withClient (package:http/http.dart:166:20)
E/flutter ( 7781): #5      get (package:http/http.dart:46:5)
E/flutter ( 7781): #6      API.getTrips (package:bike_client/API.dart:9:12)
E/flutter ( 7781): #7      _MyHomePageState._getTrips (package:bike_client/main.dart:30:9)
E/flutter ( 7781): #8      _MyHomePageState.initState (package:bike_client/main.dart:40:5)
E/flutter ( 7781): #9      StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4355:58)
E/flutter ( 7781): #10     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #11     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #12     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #13     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #14     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #15     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #16     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #17     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #18     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #19     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #20     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #21     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #22     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #23     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #24     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #25     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #26     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #27     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #28     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #29     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #30     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #31     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4381:11)
E/flutter ( 7781): #32     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #33     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #34     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #35     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #36     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #37     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #38     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #39     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #40     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #41     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #42     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #43     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #44     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4381:11)
E/flutter ( 7781): #45     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #46     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #47     Element.updateChild (package:flutter/src/wid
E/flutter ( 7781): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: SocketException: OS Error: Connection refused, errno = 111, address = localhost, port = 38884
E/flutter ( 7781): #0      IOClient.send (package:http/src/io_client.dart:33:24)
E/flutter ( 7781): <asynchronous suspension>
E/flutter ( 7781): #1      BaseClient._sendUnstreamed (package:http/src/base_client.dart:176:38)
E/flutter ( 7781): #2      BaseClient.get (package:http/src/base_client.dart:35:7)
E/flutter ( 7781): #3      get.<anonymous closure> (package:http/http.dart:46:36)
E/flutter ( 7781): #4      _withClient (package:http/http.dart:166:20)
E/flutter ( 7781): #5      get (package:http/http.dart:46:5)
E/flutter ( 7781): #6      API.getTrips (package:bike_client/API.dart:9:12)
E/flutter ( 7781): #7      _MyHomePageState._getTrips (package:bike_client/main.dart:30:9)
E/flutter ( 7781): #8      _MyHomePageState.initState (package:bike_client/main.dart:40:5)
E/flutter ( 7781): #9      StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4355:58)
E/flutter ( 7781): #10     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #11     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #12     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #13     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #14     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #15     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #16     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #17     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #18     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #19     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #20     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #21     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #22     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #23     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #24     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #25     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #26     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #27     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #28     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #29     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #30     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #31     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4381:11)
E/flutter ( 7781): #32     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #33     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #34     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #35     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #36     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #37     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #38     SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:5445:14)
E/flutter ( 7781): #39     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #40     Element.updateChild (package:flutter/src/widgets/framework.dart:2988:12)
E/flutter ( 7781): #41     ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4243:16)
E/flutter ( 7781): #42     Element.rebuild (package:flutter/src/widgets/framework.dart:3947:5)
E/flutter ( 7781): #43     ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:4206:5)
E/flutter ( 7781): #44     StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:4381:11)
E/flutter ( 7781): #45     ComponentElement.mount (package:flutter/src/widgets/framework.dart:4201:5)
E/flutter ( 7781): #46     Element.inflateWidget (package:flutter/src/widgets/framework.dart:3194:14)
E/flutter ( 7781): #47     Element.updateChild (package:flutter/src/wid
E/flutter ( 7781): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: SocketException: 
AND MUCH MORE!

Answer 1

此錯誤主要發生在您的 android AVD 或 android 設備未連接到互聯網時。 有時，開發人員嘗試從 android 設備而不是 AVD 訪問本地主機上的插件，在這種情況下，會發生相同的錯誤。 我希望這能解決你的問題。

其他場景涉及服務器端防火牆阻止的端口。

如果您發現我的答案可用，請點贊。

學習網絡

Answer 2

如果您使用帶有 localhost 的模擬器。 請將 API url 中的 IP 地址從 127.0.0.1 更改為 10.0.2.2。

Answer 3

避免出現以下問題：

• 寫入失敗
• 連接在...之前關閉
• Flutter Doctor 錯誤 - SocketException：寫入失敗（操作系統錯誤：管道損壞，errno = 32）

您需要在標題中添加正確的參數。

就我而言，這些問題發生在上傳圖像和發送 base64 編碼請求時。 我通過添加以下“連接”標頭解決了它：“保持活動”，

  final response = await this.httpClient.put(
    url,
    encoding: Utf8Codec(),
    headers: <String, String>{
      'Content-Type': 'application/json; charset=UTF-8',
      'Accept': "*/*",
      'connection': 'keep-alive',
      'Accept-Encoding' : 'gzip, deflate, br',
    },
    body: body,
  );

這個對我有用

Answer 4

我有同樣的問題。 我已經將我的 PC 連接到我的手機熱點，使用“ipconfig”獲取我的 IP 地址並將其作為我的基本 URL 像這樣

“http://PC_IP_Adress:8000/api”