概述：

App几乎都离不开与服务器的交互，本文主要讲解了flutter网络请求三种方式 flutter自带的HttpClient、 第三方库http 和 第三方库Dio 的简单实现 GET 和 POST请求，本文是笔者学习Flutter网络模块知识总结，若有问题还望不腻赐教。

一.系统自带HttpClient

1.使用中温馨提示

1.1.导入库

import 'dart:io'; // 网络请求import 'dart:convert'; // 数据解析

1.2.Uri的多种初始化方式

// 方法1Uri uri = Uri(scheme: 'https', host: 'app.xxx.com', path: homeNoviceListUrl);// 方法2Uri uri = Uri.https('app.xxx.com', homeNoviceListUrl);// uri方法3Uri uri = Uri.parse(baseUrl + homeNoviceListUrl);

2.简单使用

2.1.GET请求

// 1.1 HttpClient - get void loadData_sys_get() async {print('------loadData_sys_get--------');var httpClient = new HttpClient();var params = Map<String, String>();// uri方法1Uri uri = Uri(scheme: 'https', host: 'app.xxx.com', path: homeNoviceListUrl);// uri方法2// Uri uri = Uri.https(// 'app.xxx.com', homeNoviceListUrl);// uri方法3// Uri uri = Uri.parse(baseUrl + homeNoviceListUrl);var request = await httpClient.getUrl(uri);var headers = Map<String, String>();headers['loginSource'] = 'IOS';headers['useVersion'] = '3.1.0';headers['isEncoded'] = '1';headers['bundleId'] = 'com.xxx.xxx';request.headers.add("loginSource", "IOS");request.headers.add("useVersion", "3.1.0");request.headers.add("isEncoded", "1");request.headers.add("bundleId", "com.xxx.xxx");var response = await request.close();var responseBody = await response.transform(Utf8Decoder()).join();if (response.statusCode == HttpStatus.ok) { print('请求头：${response.headers}'); print('111请求成功代发数据为:\n $responseBody'); print('--------------'); Map data = jsonDecode(responseBody); print('222请求成功代发数据为:\n $data');} else { print('\n\n\n11111==请求失败${response.statusCode}');}}

2.2.POST请求

注意点：请求参数需要编码后放在request中

void loadData_sys_post() async {print('------loadData_sys_post--------');HttpClient httpClient = new HttpClient();// queryParameters get请求的查询参数(适用于get请求？？？是吗？？？)// Uri uri = Uri(// scheme: "https", host: "app.xxx.com", path: homeRegularListUrl);// HttpClientRequest request = await httpClient.postUrl(uri);var url = baseUrl + homeRegularListUrl;HttpClientRequest request = await httpClient.postUrl(Uri.parse(url));// 设置请求头request.headers.set("loginSource", "IOS");request.headers.set("useVersion", "3.1.0");request.headers.set("isEncoded", "1");request.headers.set("bundleId", "com.xxx.xxx");// Content-Type大小写都okrequest.headers.set('content-type', 'application/json');/// 添加请求体/// https://stackoverflow.com/questions/50278258/http-post-with-json-on-body-flutter-dart/50295533Map jsonMap = {'currentPage': '1'};request.add(utf8.encode(json.encode(jsonMap)));HttpClientResponse response = await request.close();String responseBody = await response.transform(utf8.decoder).join();if (response.statusCode == HttpStatus.ok) { print('请求成功'); print(response.headers); print(responseBody);}}

二.请求第三方库 http

1.使用中温馨提示

1.1.添加依赖

dependencies: http: ^0.12.0 #latest version

1.2.导入库

import 'package:http/http.dart' as http; //导入前需要配置

2.简单使用

2.1. GET请求

2.2.1. http - get1

void loadData_http_get() async { print('------loadData_http_get--------'); var client = http.Client(); var uri = Uri.parse(baseUrl + homeNoviceListUrl); http.Response response = await client.get(uri); if (response.statusCode == HttpStatus.ok) { print(response.body); } else { print('请求失败 code 码为${response.statusCode}'); } }

2.2. http - get简便方法（链式编程）

void loadData_http_get_convenience() async { print('------简便方法loadData_http_get_convenience--------'); var uri = Uri.parse(baseUrl + homeNoviceListUrl); http.Client().get(uri).then((http.Response response) { if (response.statusCode == HttpStatus.ok) { print(response.body); } else { print('请求失败 code 码为${response.statusCode}'); } }); }

2.2. POST请求

2.2.1. http - post

void loadData_http_post() async { print('------ loadData_http_post --------'); var headers = Map<String, String>(); headers["loginSource"] = "IOS"; headers["useVersion"] = "3.1.0"; headers["isEncoded"] = "1"; headers["bundleId"] = "com.xxx.xxx"; headers["loginSource"] = "IOS"; headers["Content\-Type"] = "application/json"; Map params = {'currentPage': '1'}; // 嵌套两层都可以，但是具体哪个好还有待确认？？？？ var jsonParams = utf8.encode(json.encode(params)); // var jsonParams = json.encode(params); var httpClient = http.Client(); var uri = Uri.parse(baseUrl + homeNoviceListUrl); http.Response response = await httpClient.post(uri, body: jsonParams, headers: headers); if (response.statusCode == HttpStatus.ok) { print(response.body); } else { print('请求失败 code 码���${response.statusCode}'); } }

2.2.2. http - Post简便方法（链式编程）

void loadData_http_post_convenience() async { print('------ loadData_http_post --------'); var headers = Map<String, String>(); headers["loginSource"] = "IOS"; headers["useVersion"] = "3.1.0"; headers["isEncoded"] = "1"; headers["bundleId"] = "com.xxx.xxx"; headers["loginSource"] = "IOS"; headers["Content\-Type"] = "application/json"; Map params = {'currentPage': '1'}; // 嵌套两层都可以，但是具体哪个好还有待确认？？？？ var jsonParams = utf8.encode(json.encode(params)); // var jsonParams = json.encode(params); var httpClient = http.Client(); var url = baseUrl + homeRegularListUrl; httpClient.post(url, body: jsonParams, headers: headers).then((response) { print("Response status: ${response.statusCode}"); print("Response body: ${response.body}"); }).whenComplete(httpClient.close); }

三.请求第三方库 Dio

1.使用中温馨提示

1.1.添加依赖

dependencies: dio: ^2.0.11 #latest version

1.2.导入库

import 'package:dio/dio.dart';

2.简单使用

2.1. GET请求

注意：Dio的get请求（baseUrl都是在dio.option.baseUrl设置的） 请求头可以在dio.option上设置，也可以在新建的option上设置,新建option是可选的

void loadData_dio_get() async { var headers = Map<String, String>(); headers['loginSource'] = 'IOS'; headers['useVersion'] = '3.1.0'; headers['isEncoded'] = '1'; headers['bundleId'] = 'com.xxx.xxx'; headers['Content-Type'] = 'application/json'; Dio dio = Dio(); dio.options.headers.addAll(headers); dio.options.baseUrl = baseUrl; Response response = await dio.get(homeNoviceListUrl); if (response.statusCode == HttpStatus.ok) { print(response.headers); print(response.data); } }

2.2. POST请求

注意：

dio.options.method设置是无效
Dio dio = Dio();
dio.options.method = 'post';

办法：
新建一个Options对象，然后在发起请求的时候进行设置：
Options option = Options(method:'post');
Response response = await dio.request(homeRegularListUrl,data:{"currentPage": "1"}, options: option);

2.2.1. dio - 方式一（baseUrl都是在dio.option.baseUrl设置的）

注意：直接在 dio.options设置除methods以外的 请求头参数

void loadData_dio_dioOfOptionsSetting() async { debugPrint( ' \n post请求 ======================= 开始请求 =======================\n'); var headers = Map<String, String>(); headers['loginSource'] = 'IOS'; headers['useVersion'] = '3.1.0'; headers['isEncoded'] = '1'; headers['bundleId'] = 'com.xxx.xxx'; headers['Content-Type'] = 'application/json'; Dio dio = Dio(); dio.options.baseUrl = baseUrl; dio.options.connectTimeout = 60000; dio.options.receiveTimeout = 60000; dio.options.headers.addAll(headers); dio.options.method = 'post'; Options option = Options(method: 'post'); // Response response = await dio.request(homeRegularListUrl, // data: {"currentPage": "1"}, options: option); Response response = await dio.post(homeRegularListUrl, data: {"currentPage": "1"}, options: option); if (response.statusCode == HttpStatus.ok) { debugPrint('请求参数： ${response.request.queryParameters}'); debugPrint( '-------------------请求成功,请求结果如下:-----------------\n \n===请求求url: ${response.request.uri.toString()} \n \n===请求 ���: \n${response.headers} \n \n===请求结果: \n${response.data}\n'); debugPrint('-------------------请求成功,请求结果打印完毕----------------'); } else { print('请求失败'); } }

2.2.2. dio - 方式二（baseUrl都是在dio.option.baseUrl设置的）

注意：在新建的option上设置请求头参数

void loadData_dio_newOptionSetting() async { debugPrint(' \n======================= 开始请求 =======================\n'); var headers = Map<String, String>(); headers['loginSource'] = 'IOS'; headers['useVersion'] = '3.1.0'; headers['isEncoded'] = '1'; headers['bundleId'] = 'com.xxx.xxx'; headers['Content-Type'] = 'application/json'; Options option = Options(method: 'post'); option.connectTimeout = 60000; option.receiveTimeout = 60000; option.headers.addAll(headers); Dio dio = Dio(); dio.options.baseUrl = baseUrl; Response response = await dio.post(homeRegularListUrl, data: {"currentPage": 1}, options: option); // Response response = await dio.request(homeRegularListUrl, // data: {"currentPage": 1}, options: option); if (response.statusCode == HttpStatus.ok) { debugPrint('请求参数： ${response.request.queryParameters}'); debugPrint( '-------------------请求成功,请求结果如下:-----------------\n \n===请求url: ${response.request.uri.toString()} \n \n===请求 头: \n${response.headers} \n \n===请求结果: \n${response.data}\n'); debugPrint('-------------------请求成功,请求结果打印完毕----------------'); } else { print('请求失败'); } }

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，谢谢大家对的支持。