话不多说自己看代码封装的比较简单，比较适合入门学习Dio。

import 'package:dio/dio.dart';

import 'Api.dart';

/*

* 封装 restful 请求

*

* GET、POST、DELETE、PATCH

* 主要作用为统一处理相关事务：

* - 统一处理请求前缀；

* - 统一打印请求信息；

* - 统一打印响应信息；

* - 统一打印报错信息；

*/

class DioUtils {

/// global dio object

static Dio dio;

/// default options

static const int CONNECT_TIMEOUT = 10000;

static const int RECEIVE_TIMEOUT = 3000;

static const String TOKEN = "1373a739fd8599909738511f41831623";

/// http request methods

static const String GET = 'get';

static const String POST = 'post';

static const String PUT = 'put';

static const String PATCH = 'patch';

static const String DELETE = 'delete';

/// 创建 dio 实例对象

static Dio createInstance() {

if (dio == null) {

/// 全局属性：请求前缀、连接超时时间、响应超时时间

var options = BaseOptions(

connectTimeout: 150000,

receiveTimeout: 150000,

responseType: ResponseType.json,

validateStatus: (status) {

// 不使用http状态码判断状态，使用AdapterInterceptor来处理(适用于标准REST风格)

return true;

},

baseUrl: Api.baseUrlDevelop,

headers: httpHeaders);

dio = new Dio(options);

}

return dio;

}

/// 清空 dio 对象

static clear() {

dio = null;

}

///Get请求

static void getHttp(

String url, {

parameters,

Function(T) onSuccess,

Function(String error) onError,

}) async {

///定义请求参数

parameters = parameters ?? {};

//参数处理

parameters.forEach((key, value) {

if (url.indexOf(key) != -1) {

url = url.replaceAll(':$key', value.toString());

}

});

try {

Response response;

Dio dio = createInstance();

response = await dio.get(url, queryParameters: parameters);

var responseData = response.data;

if (responseData['erroCode'] == 2000) {

if (onSuccess != null) {

onSuccess(responseData['result']);

}

} else {

throw Exception('erroMsg:${responseData['erroMsg']}');

}

print('响应数据：' + response.toString());

} catch (e) {

print('请求出错：' + e.toString());

onError(e.toString());

}

}

///Post请求

static void postHttp(

String url, {

parameters,

Function(T) onSuccess,

Function(String error) onError,

}) async {

///定义请求参数

parameters = parameters ?? {};

//参数处理

parameters.forEach((key, value) {

if (url.indexOf(key) != -1) {

url = url.replaceAll(':$key', value.toString());

}

});

try {

Response response;

Dio dio = createInstance();

response = await dio.post(url, queryParameters: parameters);

var responseData = response.data;

if (responseData['erroCode'] == 2000) {

if (onSuccess != null) {

onSuccess(responseData['result']);

}

} else {

throw Exception('erroMsg:${responseData['erroMsg']}');

}

print('响应数据：' + response.toString());

} catch (e) {

print('请求出错：' + e.toString());

onError(e.toString());

}

}

/// request Get、Post 请求

//url 请求链接

//parameters 请求参数

//method 请求方式

//onSuccess 成功回调

//onError 失败回调

static void requestHttp(String url,

{parameters,

method,

Function(T t) onSuccess,

Function(String error) onError}) async {

parameters = parameters ?? {};

method = method ?? 'GET';

if (method == DioUtils.GET) {

getHttp(

url,

parameters: parameters,

onSuccess: (data) {

onSuccess(data);

},

onError: (error) {

onError(error);

},

);

} else if (method == DioUtils.POST) {

postHttp(

url,

parameters: parameters,

onSuccess: (data) {

onSuccess(data);

},

onError: (error) {

onError(error);

},

);

}

}

}

/// 自定义Header

Map httpHeaders = {

'Accept': 'application/json,*/*',

'Content-Type': 'application/json',

'token': DioUtils.TOKEN

};

使用

var param = {

'taskCode ': 'XC202001020003'};

DioUtils.requestHttp(

Api.verificationSurvey,

parameters: param,

method:DioUtils.GET,

onSuccess: (data) {

},

onError: (error) {

},

);

}