http

集成http库

https://pub.dartlang.org/packages/http
添加依赖
dependencies:
  http: ^0.12.0
安装
flutter packages get
导入
import 'package:http/http.dart' as http;

常用方法

get(dynamic url, { Map<String, String> headers }) → Future<Response>

• (必须)url:请求地址
• (可选)headers:请求头

post(dynamic url, { Map<String, String> headers, dynamic body, Encoding encoding }) → Future<Response>

• (必须)url:请求地址
• (可选)headers:请求头
• (可选)body:参数
• (编码)Encoding:编码
  例子

http.post('https://flutter-cn.firebaseio.com/products.json',
            body: json.encode(param),encoding: Utf8Codec())
    .then((http.Response response) {
      final Map<String, dynamic> responseData = json.decode(response.body);
     //处理响应数据
     
    }).catchError((error) {
      print('$error错误');
    });

返回值都用到Dart Futures, 类似JavaScript中的promise
官方推荐使用async/await来调用网络请求

  void addProduct(Product product) async {
    Map<String, dynamic> param = {
      'title': product.title,
      'description': product.description,
      'price': product.price
    };
    try {
      final http.Response response = await http.post(
          'https://flutter-cn.firebaseio.com/products.json',
          body: json.encode(param),
          encoding: Utf8Codec());

      final Map<String, dynamic> responseData = json.decode(response.body);
      print('$responseData 数据');
      
    } catch (error) {
      print('$error错误');
    }
  }

用 try catch来捕获错误
两种写法都可以,个人觉得第二种语法思路更明确.