我正在工作，它应该从带有对象的Json文件列表中读取，我想在列表内部创建列表，其中第一个列表将给出主题和正文，然后应该转到该特定的另一个列表进行询问并列出每个测量的位置，但是会出现此错误
import 'package:flutter/services.dart' show rootBundle;
import 'dart:io';
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'package:test_app/InspectionDetail.dart';
import 'package:json_annotation/json_annotation.dart';
class InspetionList extends StatefulWidget {
static String tag = 'inspection-list';
@override
_InspetionListState createState() => _InspetionListState();
}
class _InspetionListState extends State<InspetionList> {
List<Lists> info = [];
List <Lists> _search =[];
TextEditingController controller = new TextEditingController();
Future <Lists> _getLists() async {
final data = await http.get(
"https://api.myjson.com/bins/qiulc");
List jsonData = json.decode(data.body);
for (int u =0; u < jsonData.length ; u++ ) {
// print(jsonData[u]["subject"]);
print(jsonData[u]["name"]);
return (jsonData[u]["subject"]);
}
}
void initState(){
super.initState();
fetch();
}
Future <List> future;
//Future <String> future ;
void fetch() async{
future = _getLists() as Future<List>;
}
onSearch(String text) async {
_search.clear();
if (text.isEmpty) {
setState(() {});
return;
}
}
// info.forEach((f){
// if(f.body.contains(text) || f.subject.contains(text)) _search.add(f);
// });
// setState(() {
// });
//
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text("List of projects"),
),
body: new Center(
child: new Column(
children: <Widget>[
new FutureBuilder(
future: _getLists(),
builder: (BuildContext context, AsyncSnapshot snapshot){
if(snapshot.hasData){
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (BuildContext context, int index){
return
ListTile(
leading: CircleAvatar(
child: Icon(Icons.settings_input_antenna),
),
title: Text(snapshot.data[index]["subject"]),
subtitle: Text(''),
);
ListTile(
title: Text(snapshot.data[index]["subject"]),
);}
);
}else if(snapshot.hasError){
return new Text("Error ${snapshot.error}");
}
})
],
),
)
);
}
}
class Lists {
final String subject;
final String body;
Inspection name;
Lists({
this.subject,
this.name,
this.body
});
factory Lists.fromJson(Map parsedJson){
return Lists(
subject: parsedJson['subject'],
body: parsedJson['body'],
name: Inspection.fromJson(parsedJson['name'])
);
}
}
class Inspection{
final String Lwidth;
final String Twidth;
final String height;
final String circumfernce;
Inspection({
this.Lwidth,
this.Twidth,
this.circumfernce,
this.height
});
factory Inspection.fromJson(Map<String, dynamic> json){
return Inspection(
Lwidth: json['Lwidth'],
Twidth: json['Twidth'],
height: json['height'],
circumfernce: json['circumfernce']
);
}}
Error :
[ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: type 'String' is not a subtype of type 'FutureOr<Lists>'
E/flutter (19254): #0 _InspetionListState._getLists (package:test_app/InspectionList.dart:45:7)
E/flutter (19254): <asynchronous suspension>
E/flutter (19254): #1 _InspetionListState.fetch (package:test_app/InspectionList.dart:59:14)
E/flutter (19254): <asynchronous suspension>
E/flutter (19254): #2 _InspetionListState.initState (package:test_app/InspectionList.dart:53:5)
E/flutter (19254): #3 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:3846:58)
E/flutter (19254): #4 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3711:5)
E/flutter (19254): #5 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2956:14)
E/flutter (19254): #6 Element.updateChild (package:flutter/src/widgets/framework.dart:2759:12)
E/flutter (19254): #7 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
E/flutter (19254): #8 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2956:14)
E/flutter (19254): #9 Element.updateChild (package:flutter/src/widgets/framework.dart:2759:12)
E/flutter (19254): #10 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:3747:16)
E/flutter (19254): #11 Element.rebuild (package:flutter/src/widgets/framework.dart:3559:5)
E/flutter (19254): #12 ComponentElement._firstBuild (package:flutter/src/widgets/framework.dart:3716:5)
E/flutter (19254): #13 ComponentElement.mount (package:flutter/src/widgets/framework.dart:3711:5)
E/flutter (19254): #14 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2956:14)
E/flutter (19254): #15 Element.updateChild (package:flutter/src/widgets/framework.dart:2759:12)
E/flutter (19254): #16 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
E/flutter (19254): #17 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2956:14)
E/flutter (19254): #18 Element.updateChild (package:flutter/src/widgets/framework.dart:2759:12)
E/flutter (19254): #19 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
E/flutter (19254): #20 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2956:14)
E/flutter (19254): #21 Element.updateChild (package:flutter/src/widgets/framework.dart:2759:12)
E/flutter (19254): #22 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
E/flutter (19254): #23 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2956:14)
E/flutter (19254): #24 Element.updateChild (package:flutter/src/widgets/framework.dart:2759:12)
E/flutter (19254): #25 SingleChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:4876:14)
E/flutter (19254): #26 Element.inflateWidget (package:flutter/src/widgets/framework.dart:2956:14)
还有Json文件
[{"body":"for test","subject":"KSA","name":{"circumfernce":"33c","Twidth":"6c","height":"55c","Lwidth":"22c"}},{"body":"for test1","subject":"USA","name":{"circumfernce":"313c","Twidth":"61c","height":"515c","Lwidth":"212c"}},{"body":"for test2","subject":"UAE","name":{"circumfernce":"333c","Twidth":"36c","height":"535c","Lwidth":"232c"}}]