标签:build amp for each payload status format init foreach
1、网络请求
1 Dio _dio = new Dio(); 2 3 Future getInformationJson(User user) async { 4 5 var url = ‘http://xxx/xxx/xxx?username=‘ + user._username + 6 ‘&password=‘ + user._password; 7 8 Response response = await _dio.get(url); 9 if (response.statusCode == HttpStatus.ok) { 10 var data = jsonDecode(response.toString()); //JSON数据的解析 11 try{ 12 data[‘payload‘][‘scores‘].forEach((v) { 13 // print(v[‘className‘]); 14 Scores score = new Scores( 15 v[‘term‘], v[‘className‘], v[‘credit‘].toString(), v[‘score‘], 16 v[‘gpa‘].toString()); 17 user._scores.add(score); 18 }); 19 20 user._avggpa = data[‘payload‘][‘gpa‘].toString(); 21 user._avgscore = data[‘payload‘][‘avg‘].toString(); 22 user._size = data[‘payload‘][‘size‘].toString(); 23 }catch(e){ 24 print(e); 25 } 26 } 27 return user; 28 }
2、异步请求(在执行界面渲染的类当中)
1 void initState() { 2 super.initState(); 3 user = new User(); 4 5 information.getInformationJson(user).then((val){ 6 user = val; 7 build(context); 8 }); 9 }
使用setState(() {});
1 @override 2 Widget build(BuildContext context){ 3 // TODO: implement build 4 5 if(user._scores == null || user._scores.length == 0){ 6 return loadingWidget(); 7 }else{ 8 print(‘main‘); 9 setState(() {}); 10 return mainWidget(); 11 } 12 }
当user获得到数据后就会重新渲染页面(loadingWidget ==> mainWidget)
标签:build amp for each payload status format init foreach
原文地址:https://www.cnblogs.com/smallstars/p/12927286.html