flutter网络编程之dio封装

一、添加依赖pubspec.yaml

dependencies:
dio: ^3.0.9

二、dio封装

2.1、创建http_service.dart文件（/lib/service/http_conf.dart），用于dio请求封装

import 'package:dio/dio.dart';
import 'dart:async';
import 'dart:io';
import '../config/index.dart';
import '../config/http_conf.dart';
 
Future request(url,{formData})async{
  try{
    Response response;
    Dio dio = new Dio();
//    dio.options.contentType = ContentType.parse('application/x-www-form-urlencoded');
    if(formData == null){
      response = await dio.post(servicePath[url]);
    }else{
      response = await dio.post(servicePath[url],data:formData);
    }
    if(response.statusCode == 200){
      return response;
    }else{
      throw Exception('后端接口异常..');
    }
  }catch(e){
    return print('error:::${e}');
  }
}

2.2、创建index.dart文件（/lib/service/ index.dart）用于引入http_conf.dart配置

export 'http_conf.dart';

2.3、创建http_conf.dart文件（lib/config/ http_conf.dart）

const base_url="http://new.163.top/api/Index/";  //公共域名
const servicePath ={
  'gmovie':base_url + 'gmovie',//获取电影
};

三、使用方法：

  定义一个方法请求数据request(请求方法,请求参数’)

void initState(){
    super.initState();
    _getvod();
  }
void _getvod(){
    request('gmovie',formData: page).then((val){
      var data = json.decode(val.toString());
      List<Map> newvodList = (data['data'] as List).cast();
      setState(() {
        vodList.addAll(newvodList);
        page++;
      });
    });
  }

四、demo以下以获取列表数据为例：

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import '../config/index.dart';
import '../service/http_service.dart';
import 'dart:convert';
import 'package:flutter_easyrefresh/easy_refresh.dart';
import 'detail_page.dart';
import 'package:date_format/date_format.dart';
 
 
 
class MoviePage extends StatefulWidget{
    _MoviePageState createState() => _MoviePageState();
}
 
class _MoviePageState extends State<MoviePage>{
 
  //电影
  int page=1;
  List<Map> vodList = [];
 
  //防止刷新处理 保持当前状态
  @override
  bool get wantKeepAlive => true;
 
  GlobalKey<RefreshHeaderState> _headerKey = new GlobalKey<RefreshHeaderState>();
  GlobalKey<RefreshFooterState> _footerKey = new GlobalKey<RefreshFooterState>();
 
  @override
  void initState(){
    super.initState();
    _getvod();
  }
 
  @override
  Widget build(BuildContext context){
//    super.build(context);
    return Scaffold(
      backgroundColor: Color.fromRGBO(244, 245, 245, 1),
      appBar: AppBar(
        title: Text(KSting.movieTitle),),
      body: FutureBuilder(
        future: request('gmovie',formData: null),
        builder: (context,snapshot){
          if(snapshot.hasData){
            return EasyRefresh(
              refreshFooter: ClassicsFooter(
                key: _footerKey,
                bgColor: Colors.white,
                textColor: KColor.refreshTextColor,
                moreInfoColor: KColor.refreshTextColor,
                showMore: true,
                moreInfo: "${formatDate(DateTime.now(), [yyyy, '-', mm, '-', dd,' ',HH, ':', nn,':', ss])}", //加载中
                loadText: KSting.loadText,
                loadReadyText: KSting.loadReadyText,
                loadingText: KSting.loadingText,
                loadedText: KSting.loadedText,
                noMoreText: KSting.noMoreText,
              ),
              refreshHeader:ClassicsHeader(
                key: _headerKey,
                refreshText: KSting.loadText,
                refreshReadyText: KSting.refreshReadyText,
                refreshingText: KSting.refreshingText,
                refreshedText: KSting.refreshedText,
                moreInfo: "${formatDate(DateTime.now(), [yyyy, '-', mm, '-', dd,' ',HH, ':', nn,':', ss])}",
                bgColor: Colors.white,
                textColor: KColor.refreshTextColor,
                moreInfoColor: KColor.refreshTextColor,
                showMore: true,
              ),
              child: ListView(
                children: <Widget>[
                  _vodBox(),//电影
                ],
              ),
              loadMore: ()async{
                _getvod();
              },
              onRefresh: _pullToRefresh,
            );
          }else{
            return Center(
                child: CircularProgressIndicator()
            );
//            return Center(
//              child: Text('加载中'),
//            );
          }
        },
 
      ),
    );
  }
  //获取电影数据
  void _getvod(){
    request('gmovie',formData: page).then((val){
      var data = json.decode(val.toString());
      List<Map> newvodList = (data['data'] as List).cast();
      setState(() {
        vodList.addAll(newvodList);
        page++;
      });
    });
  }
//  下拉刷新,必须异步async不然会报错
  Future _pullToRefresh() async {
    print('正在刷新');
    page = 1;
    vodList.clear();
    _getvod();
    return null;
  }
 
  //电影
  Widget _warpvodList(){
 
    List<Widget> listWiget =vodList.map((val){
      return InkWell(
        onTap: (){
          Navigator.of(context).push(
              MaterialPageRoute(builder: (context)=>DetailPage(
                  eachVodId: val['id'],
                  eachVodName: val['vod_name'],
                  p:1
              ))
          );
        },
        child: Container(
          width: ScreenUtil().setWidth(235),
          color: Colors.white,
          padding: EdgeInsets.only(bottom: 20.0,top: 15.0),
          child: Column(
            children: <Widget>[
              Image.network(
                val['vod_pic'],
                width: ScreenUtil().setWidth(235),
                height: 150,
                fit: BoxFit.cover,
              ),
              Text(
                val['vod_name'],
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
                style: Kfont.tvStyle,
              ),
              Text(
                  val['vod_content'],
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: Kfont.mintvStyle
              ),
            ],
          ),
        ),
      );
    }).toList();
    return Wrap(
      spacing: 2,
      children: listWiget,
    );
  }
//电影组合
  Widget _vodBox(){
    return Container(
      child: Column(
        children: <Widget>[
          _warpvodList()
        ],
      ),
    );
  }
}