6-4 使用dio來取得API資料

1. 先編輯 pubspec.yaml，安裝 https://pub.dev/packages/dio，並執行 pub get

   dependencies:
     flutter:
       sdk: flutter
   
   
     # The following adds the Cupertino Icons font to your application.
     # Use with the CupertinoIcons class for iOS style icons.
     cupertino_icons: ^1.0.2
     dio: ^3.0.10

    

2. 引入該套件

   import 'package:dio/dio.dart';

    

3. 使用之

   Future<Response> getCountriesData() async {
     Response res;
     try {
       res = await Dio().get("https://corona.lmao.ninja/v3/covid-19/countries");
       if (res.statusCode == 200 && res.data != null) {
         return res;
       }
     } on DioError catch (e) {
       print('Dio error: ${e}');
     } catch (e) {
       print('Other error: ${e}');
     }
     return res;
     // //若Widget已經掛載
     // if (mounted) {
     //   //改變狀態
     //   setState(() {});
     // }
   }

    

4. 或是用state

   Map allData = {};
   
   Future<Response> getData() async {
     try {
       Response res = await Dio().get("https://corona.lmao.ninja/v2/all");
       if (res.statusCode == 200 && res.data != null) {
         allData = res.data;
         // print(res);
       }
     } on DioError catch (e) {
       print('Dio error: ${e}');
     } catch (e) {
       print('Other error: ${e}');
     }
   
     //若Widget已經掛載
     if (mounted) {
       //改變狀態
       setState(() {});
     }
   }
   
   //State狀態初始化
   @override
   void initState() {
     // 要先做父類的State狀態初始化
     super.initState();
     //再做自己的事，如取得資料
     getData();
   }