錯誤：未為“Haberler”類型定義運算符“[]”。 flutter

Question

我將 XML 從服務轉換為 api：這是我的 model：

 // To parse this JSON data, do // // final economylistXml = economylistXmlFromJson(jsonString); import 'dart:convert'; EconomylistXml economylistXmlFromJson(String str) => EconomylistXml.fromJson(json.decode(str)); String economylistXmlToJson(EconomylistXml data) => json.encode(data.toJson()); class EconomylistXml { EconomylistXml({ required this.haberler, }); Haberler haberler; factory EconomylistXml.fromJson(Map<String, dynamic> json) => EconomylistXml( haberler: Haberler.fromJson(json["haberler"]), ); Map<String, dynamic> toJson() => { "haberler": haberler.toJson(), }; } class Haberler { Haberler({ required this.haber, }); List<Haber> haber; factory Haberler.fromJson(Map<String, dynamic> json) => Haberler( haber: List<Haber>.from(json["haber"].map((x) => Haber.fromJson(x))), ); Map<String, dynamic> toJson() => { "haber": List<dynamic>.from(haber.map((x) => x.toJson())), }; } class Haber { Haber({ required this.haberManset, required this.haberResim, required this.haberLink, required this.haberId, required this.haberVideo, required this.haberAciklama, required this.haberMetni, required this.haberKategorisi, required this.haberTarihi, required this.mansetResim, required this.izlesId, required this.yorumSay, required this.okunmaadedi, required this.anasayfamanset, required this.kategorimanset, }); String haberManset; String haberResim; String haberLink; String haberId; String haberVideo; String haberAciklama; String haberMetni; HaberKategorisi? haberKategorisi; String haberTarihi; String mansetResim; String izlesId; String yorumSay; String okunmaadedi; String anasayfamanset; String kategorimanset; factory Haber.fromJson(Map<String, dynamic> json) => Haber( haberManset: json["haber_manset"], haberResim: json["haber_resim"], haberLink: json["haber_link"], haberId: json["haber_id"], haberVideo: json["haber_video"], haberAciklama: json["haber_aciklama"], haberMetni: json["haber_metni"], haberKategorisi: haberKategorisiValues.map[json["haber_kategorisi"]], haberTarihi: json["haber_tarihi"], mansetResim: json["manset_resim"], izlesId: json["izles_id"], yorumSay: json["yorumSay"], okunmaadedi: json["okunmaadedi"], anasayfamanset: json["anasayfamanset"], kategorimanset: json["kategorimanset"], ); Map<String, dynamic> toJson() => { "haber_manset": haberManset, "haber_resim": haberResim, "haber_link": haberLink, "haber_id": haberId, "haber_video": haberVideo, "haber_aciklama": haberAciklama, "haber_metni": haberMetni, "haber_kategorisi": haberKategorisiValues.reverse[haberKategorisi], "haber_tarihi": haberTarihi, "manset_resim": mansetResim, "izles_id": izlesId, "yorumSay": yorumSay, "okunmaadedi": okunmaadedi, "anasayfamanset": anasayfamanset, "kategorimanset": kategorimanset, }; } enum HaberKategorisi { EKONOMI, DNYA } final haberKategorisiValues = EnumValues({ "Dünya": HaberKategorisi.DNYA, "Ekonomi": HaberKategorisi.EKONOMI }); class EnumValues<T> { Map<String, T> map; Map<T, String>? reverseMap; EnumValues ( this.map); Map<T, String> get reverse { if (reverseMap == null) { reverseMap = map.map((k, v) => new MapEntry(v, k)); } return reverseMap;; } }

這是我的文件，我稱之為 api

 import 'package:flutter/material.dart'; import 'package:http/http.dart' as http; import '../models/apis/economy_xml.dart'; import 'haberdetail.dart'; class Economy extends StatefulWidget { const Economy({Key? key}): super(key: key); @override State<Economy> createState() => _EconomyState(); } class _EconomyState extends State<Economy> { ScrollController? controller; final scaffoldKey = GlobalKey<ScaffoldState>(); final url = Uri.parse('https://v1.nocodeapi.com/miktadtahir/xml_to_json/htvLvoPDCwIEyTxa?url=https://www.trthaber.com/xml_mobile.php?tur=xml_genel&kategori=ekonomi&adet=20&selectEx=yorumSay,okunmaadedi,anasayfamanset,kategorimanset'); var counter; EconomylistXml? haberResult; Future callHaber() async { try{ final response = await http.get(url); if(response.statusCode == 200){ var haberler = economylistXmlFromJson(response.body); if(mounted); setState(() { haberResult = haberler; }); return haberler; } else { print(response.statusCode); } } catch(e) { print(e.toString()); } } @override void initState() { // TODO: implement initState super.initState(); callHaber(); } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( centerTitle: false, automaticallyImplyLeading: false, title: Text( 'Ekonomi Haberleri' ), ), body: Center( child: Padding( padding: const EdgeInsets.all(8.0), child: counter?= null. ListView:builder( itemCount, counter: itemBuilder, (context: index){ return Card( child: ListTile( title? Text(haberResult..haberler[index]?haberManset?,""): leading: CircleAvatar( backgroundImage? NetworkImage(haberResult..haberler[index]?haberResim?,""),): onTap. () => Navigator,push( context: MaterialPageRoute(builder: (context) => HaberDetailScreen( subtitle? haberResult..haberler[index]?haberMetni?,"": title? haberResult..haberler[index]?haberManset?,"":image? haberResult..haberler[index]?haberResim?,"")),), ); ): }): Center(child, CircularProgressIndicator( )), ), ); ); } }

我從 model 調用數據時遇到錯誤：錯誤：未為“Haberler”類型定義運算符“[]”。 我在這些線上得到這個錯誤

 child: ListTile( title: Text(haberResult?.haberler[index].haberManset??""), leading: CircleAvatar( backgroundImage: NetworkImage(haberResult?.haberler[index].haberResim??""),), onTap: () => Navigator.push( context, MaterialPageRoute(builder: (context) => HaberDetailScreen( subtitle: haberResult?.haberler[index].haberMetni??"", title: haberResult?.haberler[index].haberManset??"",image: haberResult?.haberler[index].haberResim??"")),), ),

我怎樣才能解決這個問題？ 謝謝你的幫助

Answer 1

在.haberler 之后添加.haber因為Haberler不是列表，所以Haber是一個列表，因此您可以從haber 訪問索引。

   child: ListTile(
                title: Text(haberResult?.haberler.haber[index].haberManset??""),
                leading: CircleAvatar(
                  backgroundImage: NetworkImage(haberResult?.haberler.haber[index].haberResim??""),),


                onTap: () => Navigator.push(
                  context, MaterialPageRoute(builder: (context) => HaberDetailScreen( subtitle: haberResult?.haberler.haber[index].haberMetni??"", title: haberResult?.haberler.haber[index].haberManset??"",image: haberResult?.haberler.haber[index].haberResim??"")),),
              ),