Flutter实战开发（2）——实现条形码扫描获取商品信息

实现条形码和二维码扫描

前言

上一篇博客就大致讲了一下qrscan这个插件的使用，没有具体的实现，这篇博客就来个实战吧，来做一个反盗版商品的例子

准备工具

这套课程是采用Android Studio进行开发的。当前在此之前请准备好Flutter开发环境，我这里就不进行讲解了，基础知识请到条形码和二维码扫描这篇博客学习

配置后端接口

本次项目主要是调用公开的api，可能没有及时的更新，商品的信息有点些出入
创建一个config文件夹，创建一个service_url.dart文件

const serviceUrl='http://www.mxnzp.com';
const servicePath={ 
   
  'getProductMessage':serviceUrl+'/api/barcode/goods/details',  //获取活动信息
};

编写调用接口方法

创建一个service文件夹，创建一个service_method.dart

import 'package:dio/dio.dart';
import 'dart:async';
import '../config/service_url.dart';

// 获取商品的信息
Future request(barcode) async{ 
   
  try { 
   
    print('开始获取信息');
    Response response;
    Dio dio=new Dio();
    String barCode=barcode.toString();
    var data={ 
   "barcode":barCode};
    print(data);
    response=await dio.get("http://www.mxnzp.com/api/barcode/goods/details",queryParameters: data);
    print(response.data['code']);
    if(response.data['code']==1){ 
   
      print(response.data['data']);
      return response.data['data'];
    }else{ 
   
      throw Exception('后端端口异常');
    }
  } catch (e) { 
   
    return print('ERROR:=========>${e}');
  }
}

页面布局

采用卡片布局，感觉代码蛮简单的，就不给大家解释了，直接上代码

import 'package:flutter/material.dart';
import 'package:qrscan/qrscan.dart' as scanner;
import './service/service_method.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget { 
   
  MyApp({ 
   Key key}) : super(key: key);

  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> { 
   
  String barcode = null;

  @override
  initState() { 
   
    super.initState();
  }

  @override
  Widget build(BuildContext context) { 
   
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: Text('反盗版商品'),
          
        ),
        body: Container(
          margin: EdgeInsets.only(top: 0),
          child: Column(
            //mainAxisAlignment: MainAxisAlignment.end,
            children: <Widget>[
              FutureBuilder(
                future: request(barcode),
                builder: (context,snapshot){ 
   
                  if(snapshot.hasData){ 
   
                    Map projectItem=snapshot.data;

                    return projectMessage(projectItem:projectItem);

                  }else{ 
   
                      return Center(
                        child:Text('请扫描相关的条形码')
                      );
                    }
                },
              ),
              //Text(barcode),
              MaterialButton(
                onPressed: scan,
                child: Text("Scan"),
                color: Colors.blue,
                textColor: Colors.white,
              ),
            ],
          ),
        ),
      ),
    );
  }

  Future scan() async { 
   
    try { 
   
      String barcode = await scanner.scan();
      setState(() => this.barcode = barcode);
    } on Exception catch (e) { 
   
      if (e == scanner.CameraAccessDenied) { 
   
        setState(() { 
   
          this.barcode = 'The user did not grant the camera permission!';
        });
      } else { 
   
        setState(() => this.barcode = 'Unknown error: $e');
      }
    } on FormatException { 
   
      setState(() => this.barcode = 'null (User returned using the "back"-button before scanning anything. Result)');
    } catch (e) { 
   
      setState(() => this.barcode = 'Unknown error: $e');
    }
  }
}

 class projectMessage extends StatelessWidget { 
   
    final Map projectItem;

    const projectMessage({ 
   Key key,this.projectItem}) : super(key: key);
  
    @override
    Widget build(BuildContext context) { 
   
      return Container(
        child: Card(
          child: Column(
            children: <Widget>[
              ListTile(
                title:new Text('商品名字',style: TextStyle(fontWeight: FontWeight.w500),),
                subtitle: new Text(projectItem['goodsName']),
                leading: new Icon(Icons.account_box,color: Colors.lightBlue,),
              ),
              new Divider(),
              ListTile(
                title:new Text('商品价格',style: TextStyle(fontWeight: FontWeight.w500),),
                subtitle: new Text(projectItem['price']),
                leading: new Icon(Icons.account_box,color: Colors.lightBlue,),
              ),
              new Divider(),
              ListTile(
                title:new Text('商标名称',style: TextStyle(fontWeight: FontWeight.w500),),
                subtitle: new Text(projectItem['brand']),
                leading: new Icon(Icons.account_box,color: Colors.lightBlue,),
              ),
              new Divider(),
              ListTile(
                title:new Text('生产公司',style: TextStyle(fontWeight: FontWeight.w500),),
                subtitle: new Text(projectItem['supplier']),
                leading: new Icon(Icons.account_box,color: Colors.lightBlue,),
              ),
            ],
          ),
        ),
      );
    }
  }

class Qrscan { 
   
}