在仿真器中获得Api Works，但在真实设备Flutter中无法获得Api Works

如何解决在仿真器中获得Api Works，但在真实设备Flutter中无法获得Api Works

════════ Exception caught by widgets library ═══════════════════════════════════════════════════════
type 'StateError' is not a subtype of type 'String'
The relevant error-causing widget was: 
  FutureBuilder<List<User>> file:///C:/Users/Personal/Desktop/park_parcel/lib/Json%20Service/json_Delivery_Data.dart:31:14
════════════════════════════════════════════════════════════════════════════════════════════════════

这是执行错误/错误，我必须从服务器获取Json数据，并且必须通过堆栈内的future.builder将其绑定到listview.builder！

Stack(
                  children: <Widget>[
                    Container(
                      height: _height * 1,width: _width * 1,child: DeliveryBody(),),Positioned(
                      right: _width / 8,bottom: _height / 5,child: Container(
                        height: _height * 0.18,margin: EdgeInsets.only(right: 20),alignment: Alignment.bottomRight,child: RaisedButton.icon(
                          shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(30.0),color: Colors.green[600],icon: Icon(Icons.camera_alt,color: Colors.white),label: Text(
                            'Scan Deliver',style: TextStyle(
                              color: Colors.white,onPressed: () {
                            _scanQR();
                          },

我的堆栈在这里结束，然后我从新页面获得以下代码！

Future<List<User>> _getData() async {
  var response = await http.get(Uri.encodeFull(url));
  print(response.body);
  if (response.statusCode == 200) {
    return compute(parcelList,response.body);
  } else {
    throw Exception('Unable to fetch products from the REST API');
  }
}

FutureOr<List<User>> parcelList(String responseBody) {
  //FutureOr mean Either Future values or List values
  var parsed = jsonDecode(responseBody).cast<Map<String,dynamic>>();
  return parsed.map<User>((json) => User.fromJson(json)).toList();
}

class DeliveryBody extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      child: FutureBuilder<List<User>>(
        future: _getData(),builder: (context,snapshot) {
          if (snapshot.hasError) print(Text(snapshot.error));
          return snapshot.hasData ? Parcels(item: snapshot.data) : NoParcel();
        },);
  }
}

class Parcels extends StatelessWidget {
  final List<User> item;

  const Parcels({Key key,this.item}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final _height = MediaQuery.of(context).size.height -
        MediaQuery.of(context).padding.top -
        kToolbarHeight;
    final _width = MediaQuery.of(context).size.width;

    return Builder(
      builder: (context) => Container(
        height: _height * 1,child: item != null
            ? ListView.builder(
                itemCount: item.length,itemBuilder: (BuildContext context,int index) {
                  return Column(
                    crossAxisAlignment: CrossAxisAlignment.start,children: [
                      ListTile(
                        tileColor: Colors.green[600],title: Text(
                          item[index].id.toString(),style: TextStyle(
                              fontWeight: FontWeight.w900,color: Colors.white,fontSize: 25.0),ListTile(
                        onTap: () {
                          return Column(
                            children: <Widget>[
                              Container(
                                height: _height / 10,margin: EdgeInsets.only(top: _height / 20),child: Text(
                                  'Parcel Details',textAlign: TextAlign.center,style: TextStyle(
                                    fontSize: _height / 20,decorationColor: Colors.black,textBaseline: TextBaseline.alphabetic,Container(
                                height: _height / 10,child: Text(
                                  item[index].id.toString(),],);
                        },tileColor: Colors.white,title: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,children: [
                            SizedBox(
                              height: 7.0,Text(
                              "To: " + item[index].name,style: TextStyle(
                                  fontWeight: FontWeight.w800,fontSize: 30.0),SizedBox(
                              height: 6.0,Text(item[index].parcelNumber.toUpperCase(),style: TextStyle(
                                    fontWeight: FontWeight.w700,fontSize: 24.0)),SizedBox(
                              height: 7.0,Text(item[index].address,style: TextStyle(
                                    fontWeight: FontWeight.w500,fontSize: 20.2)),Text("Parcels Size:" + item[index].parcelSize,fontSize: 20.0)),trailing: Icon(
                          Icons.arrow_forward_ios,size: 18.0,);
                },)
            : NoParcel(),);
  }
}

此代码在Android 10以下的模拟器中运行良好，并使用json数据构建了一个Lisview，但在Android 10以上的真实设备和模拟器中为我提供了以下异常/错误。Plz帮助不知道问题是什么，并且我已经在pubspec.ymal文件和Android.Xml文件中添加了所有插件，甚至还包括从用户访问Internet的权限。