一、为什么须要封装Dio
1、迁徙代码
当组件库中的方法发生改变，须要迁徙的时间，如果有多处地方用到，那么须要对使用到的每个文件都举行修改，非常的繁琐而且很容易出题目。
2、哀求库切换
当不须要Dio库的时间，我们可以试随时方便切换到别的网络库。
3、同一设置
由于一个应用步伐根本都是同一的设置方式，以是我们可以针对拦截器 、转换器 、 缓存 、同一处理惩罚错误 、署理设置、证书校验 等多个设置举行同一管理。
二、使用单利模式举行Dio封装
1、为什么使用单例模式？
每个页面都会在举行网络哀求，如果每次都要初始化一个dio，那么会增长体系不须要的开销，而使用单例模式对象一旦创建每次都是访问同一个对象，不会再实例化对象。
2、创建单例类
import 'package:dio/dio.dart';class HttpRequest { static final BaseOptions options = BaseOptions(baseUrl: ""); static final Dio dio = Dio(options); static Future<T> request<T>(String url, {String method, Map<String, dynamic> params, Interceptor inter}) async { // 1.哀求的单独设置 Options options = Options(method: method); options.headers = httpHeaders;// // 2.添加第一个拦截器// Interceptor dInter =// InterceptorsWrapper(onRequest: (RequestOptions options) {// // 1.在举行任何网络哀求的时间, 可以添加一个loading表现//// // 2.许多页面的访问必须要求携带Token,那么就可以在这里判定是有Token//// // 3.对参数举行一些处理惩罚,比如序列化处理惩罚等// print("拦截了哀求");// return options;// }, onResponse: (Response response) {// print("拦截了相应");// return response;// }, onError: (DioError error) {// print("拦截了错误");// return error;// });//// List<Interceptor> inters = [dInter];// if (inter != null) {// inters.add(inter);// }//// dio.interceptors.addAll(inters); // 3.发送网络哀求 try { Response response = await dio.request(url, data: params, options: options); return response.data; } on DioError catch (e) { return Future.error(e); } }}const httpHeaders = { 'Content-Type': 'application/json', 'X-LC-Id': 'a4Cj1Hm5aMrdhob6xGw71B5A-gzGzoHsz', 'X-LC-Key': 'XQaL1tUQC0DCQxBA9fpoR21C',};3、方法调用
HttpRequest.request(url, method: 'GET').then((res) { var list = new GHAddressModel.fromJson(res).results; setState(() { this._list = list; }); });/// 收货地点列表class GHAddressList extends StatefulWidget { @override _GHAddressListState createState() => _GHAddressListState();}class _GHAddressListState extends State<GHAddressList> { /// 地点列表 var _list = []; GlobalKey _easyRefreshKey = new GlobalKey(); _getAddressList() async { //addressDetails //shopAddress var url = "https://a4cj1hm5.api.lncld.net/1.1/classes/shopAddress"; var c = Uri.encodeComponent('-createdAt'); var d = Uri.encodeComponent('李'); url = url + '?' + "order=" + c; HttpRequest.request(url, method: 'GET').then((res) { var list = new GHAddressModel.fromJson(res).results; setState(() { this._list = list; }); }); } void initState() { super.initState(); this._easyRefreshKey.currentState; } void deactivate() { // 返回到当前页革新 var bool = ModalRoute.of(context).isCurrent; if (bool) { this._getAddressList(); } } Widget ListItem(Results results) { return InkWell( onTap: () {}, child: Container( margin: EdgeInsets.only(top: 5, bottom: 5), width: ScreenAdaper.getScreenWidth(), child: Column( children: <Widget>[ Row( mainAxisAlignment: MainAxisAlignment.spaceBetween, children: <Widget>[ Row ( children: <Widget>[ Column( crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[ Container( child: Row( children: <Widget>[ Container( width:50, child: Text( results.name, overflow: TextOverflow.ellipsis, style:TextStyle( fontSize: 18, fontWeight: FontWeight.bold, ), ), ), SizedBox( width: 10, ), Container( child: Text( results.phone, style: TextStyle(fontSize: 16,fontWeight: FontWeight.bold), ), ), ], ), ), Container( width: ScreenAdaper.getScreenWidth() - 20 - 20 - 30, child: Text( results.province + results.city + results.area + results.detailsAddress, style: TextStyle(fontSize: 14, color: Colors.black54), ), ), ], ) ], ), GestureDetector( onTap: () { Navigator.pushNamed(context, '/GHAddressEdit', arguments: { 'name': "${results.name}", 'zone': "${results.zone}", 'detailsAddress': "${results.detailsAddress}", 'phoneNumber': results.phone, 'objectId': results.objectId, }); }, child: Container( child: Icon( Icons.edit, size: 30, ), ), ), ], ), Divider(), ], ) ), ); } @override Widget build(BuildContext context) { ScreenAdaper.init(context); return Scaffold( appBar: AppBar( actions: <Widget>[ TextButton( onPressed: () { Navigator.pushNamed(context, '/GHAddressEdit'); }, child: Icon(Icons.add), ) ], title: Text("地点管理"), ), body: Container( padding: EdgeInsets.all(20), child: EasyRefresh( firstRefresh: true, key:_easyRefreshKey, onRefresh: () async { await this._getAddressList(); }, onLoad: () async { await this._getAddressList(); }, child: ListView.builder( itemBuilder: (context, index) { return ListItem(this._list[index]); }, itemCount: this._list.length, ), )), ); }}三、数据转模子
我们固然不能手写来实现，我们使用quickType来举行转化。
数据哀求后，转模子
HttpRequest.request(url, method: 'GET').then((res) { var list = new GHAddressModel.fromJson(res).results; setState(() { this._list = list; }); });GHAddressModel范例
class GHAddressModel { List<Results> results; GHAddressModel({this.results}); GHAddressModel.fromJson(Map<String, dynamic> json) { if (json['results'] != null) { results = new List<Results>(); json['results'].forEach((v) { results.add(new Results.fromJson(v)); }); } } Map<String, dynamic> toJson() { final Map<String, dynamic> data = new Map<String, dynamic>(); if (this.results != null) { data['results'] = this.results.map((v) => v.toJson()).toList(); } return data; }}class Results { String province; String area; String city; String detailsAddress; String remark; String zone; String phone; String userId; String objectId; String updatedAt; String createdAt; String name; String isDefault; Where where; Results( {this.detailsAddress, this.remark, this.province, this.area, this.city, this.zone, this.phone, this.userId, this.objectId, this.updatedAt, this.createdAt, this.name, this.isDefault, this.where}); Results.fromJson(Map<String, dynamic> json) { detailsAddress = json['detailsAddress']; if (detailsAddress == null) { detailsAddress = "暂无地点"; } remark = json['remark']; zone = json['zone']; if (zone == null) { zone = "暂无地点"; } phone = json['phone']; if (phone == null) { phone = "13800000000"; } userId = json['userId']; objectId = json['objectId']; updatedAt = json['updatedAt']; createdAt = json['createdAt']; province = json['province']; city = json['city']; area = json['area']; name = json['name']; if (name == null) { name = "没有设置"; } isDefault = json['isDefault']; where = json['where'] != null ? new Where.fromJson(json['where']) : null; } Map<String, dynamic> toJson() { final Map<String, dynamic> data = new Map<String, dynamic>(); data['detailsAddress'] = this.detailsAddress; data['remark'] = this.remark; data['zone'] = this.zone; data['phone'] = this.phone; data['userId'] = this.userId; data['objectId'] = this.objectId; data['updatedAt'] = this.updatedAt; data['createdAt'] = this.createdAt; data['name'] = this.name; data['isDefault'] = this.isDefault; data['province'] = this.province; data['city'] = this.city; data['area'] = this.area; if (this.where != null) { data['where'] = this.where.toJson(); } return data; }}class Where { String token; String userId; Where({this.token, this.userId}); Where.fromJson(Map<String, dynamic> json) { token = json['token']; userId = json['userId']; } Map<String, dynamic> toJson() { final Map<String, dynamic> data = new Map<String, dynamic>(); data['token'] = this.token; data['userId'] = this.userId; return data; }} |
