android - Get Api Works 在模拟器中但在真实设备 Flutter 中不可用

Question

════════ 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
════════════════════════════════════════════════════════════════════════════════════════════════════

这是我得到的异常/错误，我必须从服务器获取 Json 数据，它必须通过堆栈内的 future.builder 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下面的代码！

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,
        width: _width * 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,
                                width: _width * 1,
                                color: Colors.white,
                                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,
                                width: _width * 1,
                                color: Colors.white,
                                margin: EdgeInsets.only(top: _height / 20),
                                child: Text(
                                  item[index].id.toString(),
                                  textAlign: TextAlign.center,
                                  style: TextStyle(
                                    fontSize: _height / 20,
                                    decorationColor: Colors.black,
                                    textBaseline: TextBaseline.alphabetic,
                                  ),
                                ),
                              ),
                            ],
                          );
                        },
                        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)),
                            SizedBox(
                              height: 7.0,
                            ),
                            Text("Parcels Size:" + item[index].parcelSize,
                                style: TextStyle(
                                    fontWeight: FontWeight.w500,
                                    fontSize: 20.0)),
                            SizedBox(
                              height: 7.0,
                            ),
                          ],
                        ),
                        trailing: Icon(
                          Icons.arrow_forward_ios,
                          size: 18.0,
                        ),
                      ),
                    ],
                  );
                },
              )
            : NoParcel(),
      ),
    );
  }
}

此代码在 Android 版本 10 以下的模拟器中运行良好，并使用 json 数据为我构建了一个 Lisview，但在实际设备和 Android 版本 10 以上的模拟器中给了我以下异常/错误。请帮助不知道问题是什么，我已经添加我的 pubspec.ymal 文件和 Android.Xml 文件中的所有插件，甚至是用户访问 Internet 的权限..!!