FlutterDio中怎么實現二次封裝

FlutterDio中怎么實現二次封裝，很多新手對此不是很清楚，為了幫助大家解決這個難題，下面小編將為大家詳細講解，有這方面需求的人可以來學習下，希望你能有所收獲。

目錄：

DioManager：Dio輔助類NWMethod：請求方法，get、post等  NWApi：大家都知道  EntityFactory：json轉換輔助工廠，把json轉為T  BaseEntity<T>：數據基類，返回的參數為 {“code”: 0, “message”: “”, “data”: {}}  BaseListEntity<T>：數據基類2，返回的參數為 {“code”: 0, “message”: “”, “data”: []}  ErrorEntity：請求報錯基類，{“code”: 0, “message”: “”}

EntityFactory：

class EntityFactory { static T generateOBJ<T>(json) {  if (json == null) {   return null;  }//可以在這里加入任何需要并且可以轉換的類型，例如下面//  else if (T.toString() == "LoginEntity") {//   return LoginEntity.fromJson(json) as T;//  }  else {   return json as T;  } }}

BaseEntity：

class BaseEntity<T> { int code; String message; T data; BaseEntity({this.code, this.message, this.data}); factory BaseEntity.fromJson(json) {  return BaseEntity(   code: json["code"],   message: json["msg"],   // data值需要經過工廠轉換為我們傳進來的類型   data: EntityFactory.generateOBJ<T>(json["data"]),  ); }}

BaseListEntity：

class BaseListEntity<T> { int code; String message; List<T> data; BaseListEntity({this.code, this.message, this.data}); factory BaseListEntity.fromJson(json) {  List<T> mData = List();  if (json['data'] != null) {   //遍歷data并轉換為我們傳進來的類型   (json['data'] as List).forEach((v) {    mData.add(EntityFactory.generateOBJ<T>(v));   });  }  return BaseListEntity(   code: json["code"],   message: json["msg"],   data: mData,  ); } }

ErrorEntity：

class ErrorEntity { int code; String message; ErrorEntity({this.code, this.message});}

NWApi：

class NWApi { static final baseApi = "https://easy-mock.bookset.io/mock/5dfae67d4946c20a50841fa7/example/"; static final loginPath = "user/login";//接口返回：{"code": int, "message": "String", "data": {"account": "String", "password": "String"}} static final queryListPath = "/query/list";//接口返回：{"code": ing, "message": "String", "data": [int, int, String, int, String, int]} static final queryListJsonPath = "/query/listjson";//接口返回：{"code": int, "message": "String", "data": [{"account": "String", "password": "String"}， {"account": "String", "password": "String"}]}}

NWMethod：

enum NWMethod { GET, POST, DELETE, PUT}//使用：NWMethodValues[NWMethod.POST]const NWMethodValues = { NWMethod.GET: "get", NWMethod.POST: "post", NWMethod.DELETE: "delete", NWMethod.PUT: "put"};

下面就可以進行正式的封裝了：

第一步是創建Dio的單例輔助類，并初始化Dio和對Dio進行一些全局的參數設置：

import 'package:dio/dio.dart';import 'package:flutter_app/network/NWApi.dart';import 'package:flutter_app/utils/PrintUtil.dart';class DioManager { static final DioManager _shared = DioManager._internal(); factory DioManager() => _shared; Dio dio; DioManager._internal() {  if (dio == null) {   BaseOptions options = BaseOptions(    baseUrl: NWApi.baseApi,    contentType: Headers.jsonContentType,    responseType: ResponseType.json,    receiveDataWhenStatusError: false,    connectTimeout: 30000,    receiveTimeout: 3000,   );   dio = Dio(options);  } }}

第二步對請求進行封裝，在我的想法中 {“code”: 0, “message”: “”, “data”: {}} 和 {“code”: 0, “message”: “”, “data”: []} 這兩種數據是要分開兩個請求方法的：

// 請求，返回參數為 T // method：請求方法，NWMethod.POST等 // path：請求地址 // params：請求參數 // success：請求成功回調 // error：請求失敗回調 Future request<T>(NWMethod method, String path, {Map params, Function(T) success, Function(ErrorEntity) error}) async {  try {   Response response = await dio.request(path, queryParameters: params, options: Options(method: NWMethodValues[method]));   if (response != null) {    BaseEntity entity = BaseEntity<T>.fromJson(response.data);    if (entity.code == 0) {     success(entity.data);    } else {     error(ErrorEntity(code: entity.code, message: entity.message));    }   } else {    error(ErrorEntity(code: -1, message: "未知錯誤"));   }  } on DioError catch(e) {   error(createErrorEntity(e));  } } // 請求，返回參數為 List // method：請求方法，NWMethod.POST等 // path：請求地址 // params：請求參數 // success：請求成功回調 // error：請求失敗回調 Future requestList<T>(NWMethod method, String path, {Map params, Function(List) success, Function(ErrorEntity) error}) async {  try {   Response response = await dio.request(path, queryParameters: params, options: Options(method: NWMethodValues[method]));   if (response != null) {    BaseListEntity entity = BaseListEntity<T>.fromJson(response.data);    if (entity.code == 0) {     success(entity.data);    } else {     error(ErrorEntity(code: entity.code, message: entity.message));    }   } else {     error(ErrorEntity(code: -1, message: "未知錯誤"));   }  } on DioError catch(e) {   error(createErrorEntity(e));  } }

提取請求錯誤處理方法createErrorEntity：

// 錯誤信息 ErrorEntity createErrorEntity(DioError error) {  switch (error.type) {   case DioErrorType.CANCEL:{    return ErrorEntity(code: -1, message: "請求取消");   }   break;   case DioErrorType.CONNECT_TIMEOUT:{    return ErrorEntity(code: -1, message: "連接超時");   }   break;   case DioErrorType.SEND_TIMEOUT:{    return ErrorEntity(code: -1, message: "請求超時");   }   break;   case DioErrorType.RECEIVE_TIMEOUT:{    return ErrorEntity(code: -1, message: "響應超時");   }   break;   case DioErrorType.RESPONSE:{    try {     int errCode = error.response.statusCode;     String errMsg = error.response.statusMessage;     return ErrorEntity(code: errCode, message: errMsg);//     switch (errCode) {//      case 400: {//       return ErrorEntity(code: errCode, message: "請求語法錯誤");//      }//      break;//      case 403: {//       return ErrorEntity(code: errCode, message: "服務器拒絕執行");//      }//      break;//      case 404: {//       return ErrorEntity(code: errCode, message: "無法連接服務器");//      }//      break;//      case 405: {//       return ErrorEntity(code: errCode, message: "請求方法被禁止");//      }//      break;//      case 500: {//       return ErrorEntity(code: errCode, message: "服務器內部錯誤");//      }//      break;//      case 502: {//       return ErrorEntity(code: errCode, message: "無效的請求");//      }//      break;//      case 503: {//       return ErrorEntity(code: errCode, message: "服務器掛了");//      }//      break;//      case 505: {//       return ErrorEntity(code: errCode, message: "不支持HTTP協議請求");//      }//      break;//      default: {//       return ErrorEntity(code: errCode, message: "未知錯誤");//      }//     }    } on Exception catch(_) {     return ErrorEntity(code: -1, message: "未知錯誤");    }   }   break;   default: {    return ErrorEntity(code: -1, message: error.message);   }  } }

完整的 DioManager 類代碼：

import 'package:dio/dio.dart';import 'package:flutter_app/network/entity/BaseEntity.dart';import 'package:flutter_app/network/entity/BaseListEntity.dart';import 'package:flutter_app/network/entity/EntityFactory.dart';import 'package:flutter_app/network/entity/ErrorEntity.dart';import 'package:flutter_app/network/NWApi.dart';import 'package:flutter_app/network/NWMethod.dart';class DioManager { static final DioManager _shared = DioManager._internal(); factory DioManager() => _shared; Dio dio; DioManager._internal() {  if (dio == null) {   BaseOptions options = BaseOptions(    baseUrl: NWApi.baseApi,    contentType: Headers.jsonContentType,    responseType: ResponseType.json,    receiveDataWhenStatusError: false,    connectTimeout: 30000,    receiveTimeout: 3000,   );   dio = Dio(options);  } } // 請求，返回參數為 T // method：請求方法，NWMethod.POST等 // path：請求地址 // params：請求參數 // success：請求成功回調 // error：請求失敗回調 Future request<T>(NWMethod method, String path, {Map params, Function(T) success, Function(ErrorEntity) error}) async {  try {   Response response = await dio.request(path, queryParameters: params, options: Options(method: NWMethodValues[method]));   if (response != null) {    BaseEntity entity = BaseEntity<T>.fromJson(response.data);    if (entity.code == 0) {     success(entity.data);    } else {     error(ErrorEntity(code: entity.code, message: entity.message));    }   } else {    error(ErrorEntity(code: -1, message: "未知錯誤"));   }  } on DioError catch(e) {   error(createErrorEntity(e));  } } // 請求，返回參數為 List // method：請求方法，NWMethod.POST等 // path：請求地址 // params：請求參數 // success：請求成功回調 // error：請求失敗回調 Future requestList<T>(NWMethod method, String path, {Map params, Function(List<T>) success, Function(ErrorEntity) error}) async {  try {   Response response = await dio.request(path, queryParameters: params, options: Options(method: NWMethodValues[method]));   if (response != null) {    BaseListEntity entity = BaseListEntity<T>.fromJson(response.data);    if (entity.code == 0) {     success(entity.data);    } else {     error(ErrorEntity(code: entity.code, message: entity.message));    }   } else {    error(ErrorEntity(code: -1, message: "未知錯誤"));   }  } on DioError catch(e) {   error(createErrorEntity(e));  } } // 錯誤信息 ErrorEntity createErrorEntity(DioError error) {  switch (error.type) {   case DioErrorType.CANCEL:{    return ErrorEntity(code: -1, message: "請求取消");   }   break;   case DioErrorType.CONNECT_TIMEOUT:{    return ErrorEntity(code: -1, message: "連接超時");   }   break;   case DioErrorType.SEND_TIMEOUT:{    return ErrorEntity(code: -1, message: "請求超時");   }   break;   case DioErrorType.RECEIVE_TIMEOUT:{    return ErrorEntity(code: -1, message: "響應超時");   }   break;   case DioErrorType.RESPONSE:{    try {     int errCode = error.response.statusCode;     String errMsg = error.response.statusMessage;     return ErrorEntity(code: "$errCode", message: errMsg);//     switch (errCode) {//      case 400: {//       return ErrorEntity(code: errCode, message: "請求語法錯誤");//      }//      break;//      case 403: {//       return ErrorEntity(code: errCode, message: "服務器拒絕執行");//      }//      break;//      case 404: {//       return ErrorEntity(code: errCode, message: "無法連接服務器");//      }//      break;//      case 405: {//       return ErrorEntity(code: errCode, message: "請求方法被禁止");//      }//      break;//      case 500: {//       return ErrorEntity(code: errCode, message: "服務器內部錯誤");//      }//      break;//      case 502: {//       return ErrorEntity(code: errCode, message: "無效的請求");//      }//      break;//      case 503: {//       return ErrorEntity(code: errCode, message: "服務器掛了");//      }//      break;//      case 505: {//       return ErrorEntity(code: errCode, message: "不支持HTTP協議請求");//      }//      break;//      default: {//       return ErrorEntity(code: errCode, message: "未知錯誤");//      }//     }    } on Exception catch(_) {     return ErrorEntity(code: -1, message: "未知錯誤");    }   }   break;   default: {    return ErrorEntity(code: -1, message: error.message);   }  } }}

使用：

// 返回 LoginEntityDioManager().request<LoginEntity>( NWMethod.POST, NWApi.loginPath, params: {"account": "421789838@qq.com", "password": "123456"}, success: (data) {   print("success data = $data"}); }, error: (error) {   print("error code = ${error.code}, massage = ${error.message}"); });// 返回 ListDioManager().requestList<LoginEntity>( NWMethod.POST, NWApi.queryListJsonPath, params: {"account": "421789838@qq.com", "password": "123456"}, success: (data) {   print("success data = $data"}); }, error: (error) {   print("error code = ${error.code}, massage = ${error.message}"); });

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