Flutter和Dart系列九：简单的网络请求

与其说是Flutter的网络请求，倒不如说是Dart的网络请求。实际上这块是对系列八第5点的一个复习，我们直接看代码：

1. 在.yaml文件中添加http依赖，然后执行Packages get

   dependencies:
     flutter:
       sdk: flutter
     http: ^0.12.0+2
   

2. 新建一个api.dart文件

   import 'package:http/http.dart' as http;
   
   class ServerApi {
     static Future<String> getArticle() async {
       var url = "https://interface.meiriyiwen.com/article/today?dev=1";
       return _doGet(url);
     }
   
     static Future<String> _doGet(String url) async {
       http.Response response = await http.get(url);
       return response.body;
     }
   }
   

   • 就是对Future、async以及await关键字的使用，这块系列八已经介绍过
   • 应用了我们刚刚添加依赖的http库

3. 在main.dart文件中添加如下代码，我们就直接使用一个刚新建的Flutter工程：

   void _incrementCounter() {
       setState(() {
         // This call to setState tells the Flutter framework that something has
         // changed in this State, which causes it to rerun the build method below
         // so that the display can reflect the updated values. If we changed
         // _counter without calling setState(), then the build method would not be
         // called again, and so nothing would appear to happen.
   //      _counter++;
         ServerApi.getArticle().then((json) {
           print("json: $json");
         });
       });
     }
   

   改变一下FAB的点击响应，在这里发起网络请求，这里直接打印返回的json，如果在实际项目中可以对json进行解析成实体类对象然后使用。打印结果如下：