Dart实例的'未来<动态>,而不是值[重复]

0

的问题

我想创造一个应用程序,将会告诉我的天气信息,从webscraping.

我做了这个代码我不知道为什么这是给我"实例的'未来'",而不是我的价值:

import 'package:html/dom.dart' as dom;
import 'package:html/parser.dart' as parser;
import 'package:http/http.dart' as http;

class Scraper {
 List temp = [];

 Future getData(city) async {
   final response = await http
      .get(Uri.parse('https://www.google.com/search?q=temperature+$city'));

   dom.Document document = parser.parse(response.body);

   var idTemp = document.getElementById('wob_tm');

   return idTemp;
   }
 }

 void main() {
  var tempe = Scraper().getData('São Paulo');
  print(tempe);
}

为什么没有我的代码的工作?

dart flutter http request
2021-11-23 22:31:41
1

最好的答案

0
void main() async {
  var tempe = await Scraper().getData('São Paulo');
  print(tempe);
}

你需要等待您的未来,并只能使用的等待着关键词在异步的方法。 如果你想知道为什么,我建议你重新读 什么是未来和如何使用它?

2021-11-24 06:43:17

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