binanceapp/lib/backend.dart
2021-05-01 22:52:54 +03:00

80 lines
1.9 KiB
Dart

import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
Future<Btcusdt> fetchBtcusdt() async {
final response =
await http.get(Uri.https('api.binance.com', 'api/v3/ticker/24hr'));
if (response.statusCode == 200) {
return Btcusdt.fromJson(jsonDecode(response.body));
} else {
throw Exception('Failed to load Btcusdt');
}
}
class Btcusdt {
final double? valuebtc;
Btcusdt({required this.valuebtc});
factory Btcusdt.fromJson(List<dynamic> json) {
return Btcusdt(
valuebtc: double.parse(json
.where((element) => element['symbol'].contains("BTCUSDT"))
.toList()
.first['lastPrice']));
}
}
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
MyApp({Key? key}) : super(key: key);
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
late Future<Btcusdt> futureBtcusdt;
@override
void initState() {
super.initState();
futureBtcusdt = fetchBtcusdt();
}
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Fetch Data Example',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
appBar: AppBar(
title: Text('Fetch Data Example'),
),
body: Center(
child: FutureBuilder<Btcusdt>(
future: futureBtcusdt,
builder: (context, snapshot) {
if (snapshot.hasData) {
return Text(snapshot.data!.valuebtc.toString(),
style: TextStyle(fontSize: 15));
} else if (snapshot.hasError) {
return Text(
"${snapshot.error}",
style: TextStyle(fontSize: 15),
);
}
return CircularProgressIndicator();
},
),
),
),
);
}
}