晚上好！
我挂了这个电话。我有一个名为RevenueBarChart（）的小部件-有状态。此小部件使用Future Builder从API获取数据并在条形图中显示数据。我正在尝试将此条形图放在另一个有状态的小部件中。问题在于图表一直停留在加载微调器上，实际上并未更新并显示在UI中。数据从我的API中返回就很好了，我只是不知道如何实现代码来显示新图表。无论是在didChangeDepencies，didUpdateWidget还是其他方式中。我的代码如下：
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import '../providers/companies_provider.dart';
import '../charts/revenue_bar_chart.dart';
class RevenueScreen extends StatefulWidget {
static const routeName = '/revenue-screen';
@override
_RevenueScreenState createState() => _RevenueScreenState();
}
class _RevenueScreenState extends State<RevenueScreen>
with AutomaticKeepAliveClientMixin<RevenueScreen> {
@override
bool get wantKeepAlive => true;
Future _historicalData;
Future _historicalQuarterlyData;
var _isInit = true;
@override
void didChangeDependencies() {
if (_isInit) {
final companyTicker = ModalRoute.of(context).settings.arguments as String;
final loadedCompany = Provider.of<Companies>(context, listen: false)
.findByTicker(companyTicker);
_historicalData =
Companies().getHistoricalData(loadedCompany.tickerSymbol);
_historicalQuarterlyData =
Companies().getQuarterlyHistoricalData(loadedCompany.tickerSymbol);
}
_isInit = false;
super.didChangeDependencies();
}
@override
Widget build(BuildContext context) {
super.build(context);
final companyTicker = ModalRoute.of(context).settings.arguments as String;
final loadedCompany = Provider.of<Companies>(context, listen: false)
.findByTicker(companyTicker);
var truncNumber = NumberFormat.compact();
return Container(
color: Colors.black,
child: ListView(
children: <Widget>[
Column(
children: <Widget>[
Container(
height: 250,
width: double.infinity,
child: RevenueBarChart(),
),
Container(
padding: EdgeInsets.only(top: 20),
height: 50,
child: Center(
child: Text(
'Yearly Revenue',
style: TextStyle(
fontSize: 16,
fontWeight: FontWeight.bold,
color: Colors.white,
),
),
),
),
FutureBuilder(
future: _historicalData,
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.data == null) {
return Container(
height: 50,
child: Center(
child: CircularProgressIndicator(),
),
);
} else {
return Container(
decoration: BoxDecoration(
color: Colors.black,
border: Border.all(
color: Colors.grey,
width: 0.5,
),
borderRadius: BorderRadius.circular(10),
),
height: 225,
width: double.infinity,
margin: EdgeInsets.only(left: 60, right: 60),
child: ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (BuildContext context, int index) {
return ListTile(
dense: true,
leading: Text(
snapshot.data[index]['date'].toString(),
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.bold,
),
),
trailing: Text(
truncNumber
.format(snapshot.data[index]['revenue'])
.toString(),
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.bold,
),
),
);
},
),
);
}
},
),
SizedBox(
height: 30,
width: 1,
),
Container(
padding: EdgeInsets.only(top: 20),
height: 50,
child: Center(
child: Text(
'Quarterly Revenue',
style: TextStyle(
fontSize: 16,
fontWeight: FontWeight.bold,
color: Colors.white,
),
),
),
),
FutureBuilder(
future: _historicalQuarterlyData,
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.data == null) {
return Container(
height: 50,
child: Center(
child: CircularProgressIndicator(),
),
);
} else {
return Container(
decoration: BoxDecoration(
color: Colors.black,
border: Border.all(
color: Colors.grey,
width: 0.5,
),
borderRadius: BorderRadius.circular(10),
),
height: 225,
width: double.infinity,
margin: EdgeInsets.only(left: 60, right: 60),
child: ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (BuildContext context, int index) {
return ListTile(
dense: true,
leading: Text(
snapshot.data[index]['date'].toString(),
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.bold,
),
),
trailing: Text(
truncNumber
.format(snapshot.data[index]['revenue'])
.toString(),
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.bold,
),
),
);
},
),
);
}
},
),
SizedBox(
height: 50,
width: 5,
),
],
),
],
),
);
}
}
提前谢谢！
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import 'package:stockmarketapp/models/financial_modeling_prep_HD.dart';
import 'package:syncfusion_flutter_charts/charts.dart';
import '../providers/companies_provider.dart';
class RevenueBarChart extends StatefulWidget with ChangeNotifier {
@override
_RevenueBarChartState createState() => _RevenueBarChartState();
}
class _RevenueBarChartState extends State<RevenueBarChart> with ChangeNotifier {
Future<List<IncomeStatementBC>> _revenueDataForChart;
var _isInit = true;
bool isFirstLabel;
@override
void didChangeDependencies() {
if (_isInit) {
final companyTicker = ModalRoute.of(context).settings.arguments as String;
final loadedCompany = Provider.of<Companies>(context, listen: false)
.findByTicker(companyTicker);
_revenueDataForChart =
Companies().getIncomeStatement(loadedCompany.tickerSymbol);
}
_isInit = false;
super.didChangeDependencies();
}
@override
Widget build(BuildContext context) {
final companyTicker = ModalRoute.of(context).settings.arguments as String;
final loadedCompany = Provider.of<Companies>(context, listen: false)
.findByTicker(companyTicker);
var truncNumber = NumberFormat.compact();
isFirstLabel = true;
final List<Color> color = <Color>[];
color.add(Colors.black12.withOpacity(1));
color.add(Color.fromRGBO(0, 128, 255, .5));
color.add(Color.fromRGBO(0, 128, 255, .7));
color.add(Color.fromRGBO(0, 128, 255, .9));
final List<double> stops = <double>[];
stops.add(0);
stops.add(0.3);
stops.add(.4);
stops.add(.6);
final LinearGradient gradients =
LinearGradient(
colors: color,
stops: stops,
transform: GradientRotation(
540.toDouble() * 3.14 / 270
),
begin: Alignment.bottomCenter,
end: Alignment.topCenter,
);
return Container(
height: 250,
width: double.infinity,
child: FutureBuilder<List<IncomeStatementBC>>(
future: _revenueDataForChart,
builder: (BuildContext context, AsyncSnapshot<List<IncomeStatementBC>> snapshot) {
if (snapshot.data != null) {
return SfCartesianChart(
onAxisLabelRender: (AxisLabelRenderArgs args) {
if (args.axisName == 'primaryYAxis' && isFirstLabel) {
args.text = ' ';
isFirstLabel = false;
}
},
plotAreaBackgroundColor: Colors.black,
zoomPanBehavior: ZoomPanBehavior(enablePanning: true),
trackballBehavior: TrackballBehavior(
enable: true,
activationMode: ActivationMode.singleTap,
tooltipSettings: InteractiveTooltip(
enable: true,
color: Colors.black87,
format: 'point.y',
)
),
margin: EdgeInsets.only(
left: 20,
right: 20,
top: 10,
bottom: 10
),
primaryXAxis: CategoryAxis(
labelAlignment: LabelAlignment.start,
maximumLabels: 5,
labelStyle: TextStyle(color: Colors.white),
majorGridLines: MajorGridLines(color: Colors.grey, width: 0),
majorTickLines: MajorTickLines(size: 0),
),
primaryYAxis: NumericAxis(
numberFormat: NumberFormat.compact(),
opposedPosition: true,
tickPosition: TickPosition.inside,
maximumLabels: 2,
labelStyle: TextStyle(color: Colors.white),
labelAlignment: LabelAlignment.start,
majorGridLines: MajorGridLines(color: Colors.grey, width: 0),
majorTickLines: MajorTickLines(size: 0),
minorGridLines: MinorGridLines(color: Colors.grey, width: 0),
minorTickLines: MinorTickLines(size: 0)
),
series: <ChartSeries<IncomeStatementBC, String>>[
ColumnSeries<IncomeStatementBC, String>(
gradient: gradients,
dataSource: snapshot.data,
xValueMapper: (IncomeStatementBC data, _) => data.date,
yValueMapper: (IncomeStatementBC data, _) => data.revenue,
)
],
);
} else {
return Center(
child: CircularProgressIndicator(),
);
}
},
),
);
}
}