封装网络请求, 我使用了 Dio 库。

    HttpUtil.dart

    1. import 'package:dio/dio.dart';
    3. class HttpUtil {
    4.   static HttpUtil instance;
    5.   Dio dio;
    6.   BaseOptions options;
    7.   String baseUrl = "https://5d5a45132257cc001496241b.mockapi.io/api/";
    9.   static HttpUtil getInstance() {
    10.     print('getInstance');
    11.     if (instance == null) {
    12.       instance = new HttpUtil();
    13.     }
    14.     return instance;
    15.   }
    17.   HttpUtil() {
    18.     options = BaseOptions(
    19.       // 请求基地址,可以包含子路径，如: "//www.google.com/api/".
    20.       baseUrl: baseUrl,
    21.       //连接服务器超时时间，单位是毫秒.
    22.       connectTimeout: 10000,
    24.       ///  响应流上前后两次接受到数据的间隔，单位为毫秒。如果两次间隔超过[receiveTimeout]，
    25.       ///  [Dio] 将会抛出一个[DioErrorType.RECEIVE_TIMEOUT]的异常.
    26.       ///  注意: 这并不是接收数据的总时限.
    27.       receiveTimeout: 3000,
    28.       headers: {},
    29.     );
    30.     dio = new Dio(options);
    31.   }
    33.   resolve(List api, {data, options, cancelToken}) async {
    34.     switch (api[1]) {
    35.       case 'get':
    36.         return await this.get(
    37.             api[0],
    38.             data: data,
    39.             options: options,
    40.             cancelToken: cancelToken
    41.         );
    42.         break;
    43.       case 'post':
    44.         return await this.post(
    45.             api[0],
    46.             data: data,
    47.             options: options,
    48.             cancelToken: cancelToken
    49.         );
    50.         break;
    51.       default:
    52.         break;
    53.     }
    54.   }
    56.   get(url, {data, options, cancelToken}) async {
    57.     print('get请求启动! url：$url ,body: $data');
    58.     Response response;
    59.     try {
    60.       response = await dio.get(
    61.         url,
    62.         queryParameters: data,
    63.         cancelToken: cancelToken,
    64.       );
    65.       print('get请求成功! response.data：${response.data}');
    66.     } on DioError catch (e) {
    67.       if (CancelToken.isCancel(e)) {
    68.         print('get请求取消! ' + e.message);
    69.       }
    70.       print('get请求发生错误：$e');
    71.     }
    72.     return response.data;
    73.   }
    75.   post(url, {data, options, cancelToken}) async {
    76.     print('post请求启动! url：$url ,body: $data');
    77.     Response response;
    78.     try {
    79.       response = await dio.post(
    80.         url,
    81.         data: data,
    82.         cancelToken: cancelToken,
    83.       );
    84.       print('post请求成功! response.data：${response.data}');
    85.     } on DioError catch (e) {
    86.       if (CancelToken.isCancel(e)) {
    87.         print('post请求取消! ' + e.message);
    88.       }
    89.       print('post请求发生错误：$e');
    90.     }
    91.     return response.data;
    92.   }
    93. }

    Api.dart

    1. class Api {
    2.   static List USER_LIST = ['user', 'get'];
    3. }

    使用方式：

    1. Future getData() async {
    2.   var data = {'pageIndex': 1, 'pageSize': 10};
    3.   var response = await HttpUtil().resolve(Api.USER_LIST, data: data);
    4.   print(response);
    5.   print(response is List); // true
    6.   print(response[0] is Map); // true
    7. }

    可以看到, 返回的 json 数据自动转化为了 List 或 Map 格式的数据。