Flutter GetX 控制器获取空值而不是数据

Question

我有一个 API（它确实有效并且 return 是一个响应，我什至可以在 return 语句上方看到响应 1 行），但出于某种原因，当数据应该传递给变量时，我收到 null，而不是 returned 值。

服务 return 数据 我确实从 API 获取值，至少它说明return.

之前的变量中有数据

应该包含数据的resp变量显示值为空。

api_service.dart <= Returns 一个值

import 'dart:io';
import 'package:http/http.dart' as http;
import 'dart:convert';

class RemoteServices {
  static var client = http.Client();

  static Future sendImageForAnalysis(String filename) async {
    var request =
        http.MultipartRequest('POST', Uri.parse("http://10.0.2.2:8000/api"));

    request.files.add(http.MultipartFile('picture',
        File(filename).readAsBytes().asStream(), File(filename).lengthSync(),
        filename: filename.split("/").last));

    var res = await request.send();
    if (res.statusCode == 200) {
      http.Response.fromStream(res)
          .then((response) {
            var dataAsJson = json.decode(response.body);
            /* The variable from above does have data, it's not empty and none of the errors appears*/
            return dataAsJson;
          })
          .catchError((error) => print('Something went wrong')) /* Error is not showing */
          .whenComplete(() => print('Got data from the server'));
    } else {
      /* Code does not get here */
      return {'name': 'x'};
    }
  }
}

controller_results.dart <= 显示空值，而不是值。

import 'package:face_search/services/api_service.dart';
import 'package:get/get.dart';

class ResultsController extends GetxController {
  final data = {}.obs;
  final name = ''.obs;

  void getItemData(imagePath) async {
    var resp = await RemoteServices.sendImageForAnalysis(imagePath);
    print(resp); /* This is empty for some reason */
    if (resp != null) {
      data.value = resp;
    }
  }
}

Answer 1

api return json 的结果是？如果它 return json 为什么不尝试为它创建一个模型并调用控制器上的列表，这样您就可以自由地知道它是否有数据 return.

Answer 2

您在 http.Response.fromStream(res) 之前缺少 return。

Flutter GetX 控制器获取空值而不是数据

Flutter GetX controller getting null instead of data

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