Flutter 后台数据接口调试 业务分离

建立数据模型层，我们的业务逻辑分开，然后进行后台数据的调试。按照真实项目的开发目录接口和文件组织来进行开发。

建立商品详细模型

我们还是用快速生成的方式建立一下商品详细页的接口模型，有这样一段从后端获取的JSON，直接用快速生成的方式，把这段JSON生成模型，然后进行必要的修改。

{"code":"0","message":"success","data":{"goodInfo":{"image5":"","amount":10000,"image3":"","image4":"","goodsId":"ed675dda49e0445fa769f3d8020ab5e9","isOnline":"yes","image1":"http://images.baixingliangfan.cn/shopGoodsImg/20190116/20190116162618_2924.jpg","image2":"","goodsSerialNumber":"6928804011173","oriPrice":3.00,"presentPrice":2.70,"comPic":"http://images.baixingliangfan.cn/compressedPic/20190116162618_2924.jpg","state":1,"shopId":"402880e860166f3c0160167897d60002","goodsName":"可口可乐500ml/瓶","goodsDetail":"<img src="http://images.baixingliangfan.cn/shopGoodsDetailImg/20171224/20171224081109_5060.jpg" width="100%" height="auto" alt="" /><img src="http://images.baixingliangfan.cn/shopGoodsDetailImg/20171224/20171224081109_1063.jpg" width="100%" height="auto" alt="" /><img src="http://images.baixingliangfan.cn/shopGoodsDetailImg/20171224/20171224081110_8029.jpg" width="100%" height="auto" alt="" /><img src="http://images.baixingliangfan.cn/shopGoodsDetailImg/20171224/20171224081110_1074.jpg" width="100%" height="auto" alt="" /><img src="http://images.baixingliangfan.cn/shopGoodsDetailImg/20171224/20171224081110_8439.jpg" width="100%" height="auto" alt="" /><img src="http://images.baixingliangfan.cn/shopGoodsDetailImg/20171224/20171224081110_6800.jpg" width="100%" height="auto" alt="" />"},"goodComments":[{"SCORE":5,"comments":"果断卸载，2.5个小时才送到","userName":"157******27","discussTime":1539491266336}],"advertesPicture":{"PICTURE_ADDRESS":"http://images.baixingliangfan.cn/advertesPicture/20190113/20190113134955_5825.jpg","TO_PLACE":"1"}}}

复制上面的的代码，代开下面的地址，利用JSON代码，快速生成Model模型。

https://javiercbk.github.io/json_to_dart/

在lib/model文件夹下新建立details.dart文件，然后把生成的代码拷贝到下面。

class DetailsModel {
  String code;
  String message;
  DetailsGoodsData data;

  DetailsModel({this.code, this.message, this.data});

  DetailsModel.fromJson(Map<String, dynamic> json) {
    code = json['code'];
    message = json['message'];
    data = json['data'] != null ? new DetailsGoodsData.fromJson(json['data']) : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['code'] = this.code;
    data['message'] = this.message;
    if (this.data != null) {
      data['data'] = this.data.toJson();
    }
    return data;
  }
}

class DetailsGoodsData {
  GoodInfo goodInfo;
  List<GoodComments> goodComments;
  AdvertesPicture advertesPicture;

  DetailsGoodsData({this.goodInfo, this.goodComments, this.advertesPicture});

  DetailsGoodsData.fromJson(Map<String, dynamic> json) {
    goodInfo = json['goodInfo'] != null
        ? new GoodInfo.fromJson(json['goodInfo'])
        : null;
    if (json['goodComments'] != null) {
      goodComments = new List<GoodComments>();
      json['goodComments'].forEach((v) {
        goodComments.add(new GoodComments.fromJson(v));
      });
    }
    advertesPicture = json['advertesPicture'] != null
        ? new AdvertesPicture.fromJson(json['advertesPicture'])
        : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.goodInfo != null) {
      data['goodInfo'] = this.goodInfo.toJson();
    }
    if (this.goodComments != null) {
      data['goodComments'] = this.goodComments.map((v) => v.toJson()).toList();
    }
    if (this.advertesPicture != null) {
      data['advertesPicture'] = this.advertesPicture.toJson();
    }
    return data;
  }
}

class GoodInfo {
  String image5;
  int amount;
  String image3;
  String image4;
  String goodsId;
  String isOnline;
  String image1;
  String image2;
  String goodsSerialNumber;
  double oriPrice;
  double presentPrice;
  String comPic;
  int state;
  String shopId;
  String goodsName;
  String goodsDetail;

  GoodInfo(
      {this.image5,
      this.amount,
      this.image3,
      this.image4,
      this.goodsId,
      this.isOnline,
      this.image1,
      this.image2,
      this.goodsSerialNumber,
      this.oriPrice,
      this.presentPrice,
      this.comPic,
      this.state,
      this.shopId,
      this.goodsName,
      this.goodsDetail});

  GoodInfo.fromJson(Map<String, dynamic> json) {
    image5 = json['image5'];
    amount = json['amount'];
    image3 = json['image3'];
    image4 = json['image4'];
    goodsId = json['goodsId'];
    isOnline = json['isOnline'];
    image1 = json['image1'];
    image2 = json['image2'];
    goodsSerialNumber = json['goodsSerialNumber'];
    oriPrice = json['oriPrice'];
    presentPrice = json['presentPrice'];
    comPic = json['comPic'];
    state = json['state'];
    shopId = json['shopId'];
    goodsName = json['goodsName'];
    goodsDetail = json['goodsDetail'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['image5'] = this.image5;
    data['amount'] = this.amount;
    data['image3'] = this.image3;
    data['image4'] = this.image4;
    data['goodsId'] = this.goodsId;
    data['isOnline'] = this.isOnline;
    data['image1'] = this.image1;
    data['image2'] = this.image2;
    data['goodsSerialNumber'] = this.goodsSerialNumber;
    data['oriPrice'] = this.oriPrice;
    data['presentPrice'] = this.presentPrice;
    data['comPic'] = this.comPic;
    data['state'] = this.state;
    data['shopId'] = this.shopId;
    data['goodsName'] = this.goodsName;
    data['goodsDetail'] = this.goodsDetail;
    return data;
  }
}

class GoodComments {
  int sCORE;
  String comments;
  String userName;
  int discussTime;

  GoodComments({this.sCORE, this.comments, this.userName, this.discussTime});

  GoodComments.fromJson(Map<String, dynamic> json) {
    sCORE = json['SCORE'];
    comments = json['comments'];
    userName = json['userName'];
    discussTime = json['discussTime'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['SCORE'] = this.sCORE;
    data['comments'] = this.comments;
    data['userName'] = this.userName;
    data['discussTime'] = this.discussTime;
    return data;
  }
}

class AdvertesPicture {
  String pICTUREADDRESS;
  String tOPLACE;

  AdvertesPicture({this.pICTUREADDRESS, this.tOPLACE});

  AdvertesPicture.fromJson(Map<String, dynamic> json) {
    pICTUREADDRESS = json['PICTURE_ADDRESS'];
    tOPLACE = json['TO_PLACE'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['PICTURE_ADDRESS'] = this.pICTUREADDRESS;
    data['TO_PLACE'] = this.tOPLACE;
    return data;
  }
}

添加商品详情的接口

'getGoodDetailById':serviceUrl+'wxmini/getGoodDetailById',//商品详细信息

Provide建立

在实际开发中，我们是将业务逻辑和UI表现分开的，所以线建立一个Provide文件，所有业务逻辑将写在Provide里，然后pages文件夹里只写UI层面的东西。这样就把业务逻辑和UI进行了分离。

在lib/provide/文件夹下新建立一个details_info.dart文件，这个文件就是写商品详细页相关的业务逻辑的。

import 'package:flutter/material.dart';
import '../model/details.dart';
import '../service//service_method.dart';
import 'dart:convert/';

class DetailsInfoProvide with ChangeNotifier{ 
  DetailsModel goodsInfo = null; //商品详情的变量

  //从后台获取商品数据
  getGoodsInfo(String id){ //传递商品id
    var formData = {'goodId':id};
    request('getGoodDetailById', formData: formData).then((val){
      var responseData = json.decode(val.toString()); //从后台得到的数据
      print(responseData);
      goodsInfo = DetailsModel.fromJson(responseData);
      notifyListeners(); //通知

    });

  }

}

先引入刚建立好的Model，然后引入service_method.dart文件。声明DetailsInfoProvidel类，在类里边声明一个DetailsModel类型的 goodsInfo变量，初始值甚至成null，然后写一个从后台获取数据的方法,命名为getGoodsInfo。

Provide全局注入

在main.dart中注入，先引入details_info.dart文件，然后声明变量、注入

var detailsInfoProvide = DetailsInfoProvide();

..provide(Provider<DetailsInfoProvide>.value(detailsInfoProvide));

在UI调试接口

直接在pages文件夹的details_page.dart文件里，写一个_getBackInfo方法，然后在build方法里使用一下。 如果控制台打印出商品详细的数据，说明接口已经调通。

  void _getBackInfo(BuildContext context) async{
    await Provide.value<DetailsInfoProvide>(context).getGoodsInfo(goodsId);
    print('加载完成...........');
  }

完整代码：

import 'package:flutter/material.dart';
import 'package:provide/provide.dart';
import '../provide/detail_info.dart';

class DetailsPage extends StatelessWidget {
  final String goodsId;
  DetailsPage(this.goodsId); //构造函数最新写法

  @override
  Widget build(BuildContext context) {
    _getBackInfo(context);
    return Container(
      child: Center(
        child: Text('商品ID：${goodsId}'),
      ),
    );
  }

  void _getBackInfo(BuildContext context) async{
    await Provide.value<DetailsInfoProvide>(context).getGoodsInfo(goodsId);
    print('加载完成...........');
  }

}

运行测试，控制台成功打印出商品详细的数据，说明接口已经调通。

详细页UI主页面架构搭建

details_page页面主要修改build方法。代码如下:

Widget build(BuildContext context) {
    
    return Scaffold(
      appBar: AppBar(
        leading: IconButton( //返回按钮
          onPressed: (){
            Navigator.pop(context); //返回上级页面
          },
          icon: Icon(Icons.arrow_back),
        ),
        title: Text('商品详细页'),
      ),
      body: FutureBuilder(
        future: _getBackInfo(context),
        builder: (context, snapshot){
          if(snapshot.hasData){
            return Container(
              child: Column(
                children: <Widget>[
                  Text('商品ID:${goodsId}')
                ],
              ),
            );
          }else{
            return Text('加载中......');
          }
        },
      ),
    );
  }

在body区域,使用了FutureBuilder Widget ，可以实现异步建在的效果。并且在可以判断snapshot.hasData进行判断是否在加载还是在加载中。

_getBackInfo方法的修改

在build方法里使用了FutureBuilder部件，所以使用的后台得到数据的方法，也要相应的做出修改，要最后返回一个Future 部件。代码如下:

Future _getBackInfo(BuildContext context) async{
    await Provide.value<DetailsInfoProvide>(context).getGoodsInfo(goodsId);
    return '完成加载';
}

完整代码如下：

import 'package:flutter/material.dart';
import 'package:provide/provide.dart';
import '../provide/detail_info.dart';

class DetailsPage extends StatelessWidget {
  final String goodsId;
  DetailsPage(this.goodsId); //构造函数最新写法

  @override
  Widget build(BuildContext context) {
    
    return Scaffold(
      appBar: AppBar(
        leading: IconButton( //返回按钮
          onPressed: (){
            Navigator.pop(context); //返回上级页面
          },
          icon: Icon(Icons.arrow_back),
        ),
        title: Text('商品详细页'),
      ),
      body: FutureBuilder(
        future: _getBackInfo(context),
        builder: (context, snapshot){
          if(snapshot.hasData){
            return Container(
              child: Column(
                children: <Widget>[
                  Text('商品ID:${goodsId}')
                ],
              ),
            );
          }else{
            return Text('加载中......');
          }
        },
      ),
    );
  }

  Future _getBackInfo(BuildContext context) async{
    await Provide.value<DetailsInfoProvide>(context).getGoodsInfo(goodsId);
    return '完成加载';
  }

}