Flutter http api获取json密钥

Question

我在一个变量中有这样的json数据，我如何逐一使用这里的数据。

我想像这个一样使用

开始时间：07.00-结束：22.00

Padding(
padding: const EdgeInsets.only(left: 6, top:2,right: 5,bottom:5),
child: Align(
alignment: Alignment.centerLeft,
child: Container(
child: Text(widget.company.worktime.toString(),style: TextStyle(fontSize: 16),),
),
),
),

结果；

[{quot；开始"："07:00"，"结束"："22:00"，"关闭"0}，
{"结束"："22:00"，"关闭"：0}，
{"开始"："07:00"，"结束"："22:00"，"关闭"：0}，
："22:00"，"关闭"：0}，
{"开始"："07:00"，"结束"："22:00&"，"闭合"：0}]

Answer 1

创建Worktime模型/数据类

class Worktime {
String? start;
String? end;
int? close;
Worktime({this.start, this.end, this.close});
Worktime.fromJson(Map<String, dynamic> json) {
start = json['start'];
end = json['end'];
close = json['close'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = {};
data['start'] = start;
data['end'] = end;
data['close'] = close;
return data;
}
}

创建json列表数据解析器方法

List<Worktime> wrktimesFromJson(String str) =>
List<Worktime>.from(jsonDecode(str).map((x) => Worktime.fromJson(x)));

如果您的列表数据很大，并且需要更好的性能，请尝试使用ListView.builder小部件，否则对于简单用例/小数据集，请使用Column with SingleChildScrollView。

对于ListView.builder:

class _MyHomePageState extends State<MyHomePage> {
List<Worktime> worktimes = [];
@override
void initState() {
worktimes = wrktimesFromJson(widget.company.worktime.toString());
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Padding(
padding: const EdgeInsets.only(left: 6, top: 2, right: 5, bottom: 5),
child: ListView.builder(
itemCount: worktimes.length,
itemBuilder: (BuildContext context, int index) {
var worktime = worktimes[index];
return Text(
"Start : ${worktime.start} - End : ${worktime.end}",
style: const TextStyle(fontSize: 16),
);
},
),
),
);
}
}

对于具有SingleChildScrollView的列：

class _MyHomePageState extends State<MyHomePage> {
List<Worktime> worktimes = [];
@override
void initState() {
worktimes = wrktimesFromJson(widget.company.worktime.toString());
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: SingleChildScrollView(
child: Padding(
padding: const EdgeInsets.only(left: 6, top: 2, right: 5, bottom: 5),
child: Column(
children: worktimes.map((worktime) {
return Text(
"Start : ${worktime.start} - End : ${worktime.end}",
style: const TextStyle(fontSize: 16),
);
}).toList(),
),
),
),
);
}
}

Answer 2

需要最少的代码来确保。但是如果json数据包含在一个数组中，则可以调用索引数据

或者可以使用这个https://api.flutter.dev/flutter/widgets/ListView-class.html