Question

我正在尝试获取由android studio开发的flutter应用程序，以连接到本地托管的C＃API。在IIS Express上运行api会得到一个https://localhost:44364/api/trip的URL，我相信与模拟器中的Android Studio中的http://10.0.2.2:44364/api相关。

我正在尝试通过API从数据库中获取行程列表。邮递员工作得很好。

我遇到多个错误。我尝试了模拟器，也尝试了直接插入电话并将地址切换到我的IP地址。我什至尝试将api切换为在控制台而不是IIS中运行。什么都行不通。

我确实尝试通过模拟器浏览器访问api，但被告知该站点不安全，导致我认为这是证书问题。

flutter项目非常简单，处于起步阶段，我仍在学习如何对其进行编程。

这是三个flutter文件和错误列表。

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);
  }
}

Trip.dart

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};
  }
}

控制台

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

此错误主要是在您的android AVD或android设备未连接到互联网时发生的。有时，开发人员尝试从android设备而非AVD访问localhost上的插件，在这种情况下，会发生相同的错误。我希望这能解决您的问题。

其他情况包括服务器端防火墙阻止了端口。

如果您认为我的回答有用，请投票。

Learn Cybers

Answer 2

如果将仿真器与localhost一起使用。请在API网址中将IP地址从127.0.0.1更改为10.0.2.2。

Answer 3

避免以下问题：

写入失败
连接在...之前关闭
Flutter Doctor 错误 - SocketException：写入失败（操作系统错误：管道损坏，errno = 32）

您需要在标题中添加正确的参数。

就我而言，这些问题发生在上传图片和发送 base64 编码请求时。我通过添加以下“连接”标头解决了这个问题：“保持活动”，

  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,
  );

它对我有用

Answer 4

我遇到了同样的问题。我已经将我的 PC 连接到我的手机热点，使用“ipconfig”获取我的 IP 地址并将其作为我的基本 URL 像这样

"http://PC_IP_Adress:8000/api"

Flutter未处理的异常：SocketException：操作系统错误：连接被拒绝，errno = 111

4 个答案: