Flutter Snapshot.hasData 总是返回 true

Question

我需要从服务器获取数据，有时数据可能是空的来自 logcat 的响应是数据 snapshot.data 正在返回我的模型 Instance of 'MyItems' 的实例以及来自服务器的响应数据不可用是

{
    "data": []
}

问题是 snapshot.hasData 对于我测试过的空响应总是返回 true snapshot.data == null 仍然是 true。

型号class

import 'dart:convert';

MyItems myItemsFromJson(String str) => MyItems.fromJson(json.decode(str));

String myItemsToJson(MyItems data) => json.encode(data.toJson());

class MyItems {
  MyItems({
    this.dataa,
  });

  List<Datumm> dataa;

  factory MyItems.fromJson(Map<String, dynamic> json) => MyItems(
    dataa: List<Datumm>.from(json["data"].map((x) => Datumm.fromJson(x))),
  );

  Map<String, dynamic> toJson() => {
    "data": List<dynamic>.from(dataa.map((x) => x.toJson())),
  };
}

class Datumm {
  Datumm({
    this.userId,
    this.Name,
    this.MiddelName,
  
  });

  String userId;
  String Name;
  String MiddelName;
 

  factory Datumm.fromJson(Map<String, dynamic> json) => Datumm(
    userId: json["user_id"],
    Name: json["Name"],
    MiddelName: json["MiddleName"],
  
  );

  Map<String, dynamic> toJson() => {
    "user_id": userId,
    "Name": crbtCode,
    "MiddelName": artistName,
    
  };
}

我的未来api来电

 Future<MyItems> getUdata(String aName) async {
        var url =
            'https://cvbgng.com/test/${aName}';
    
        final response = await http.get(url).timeout(Duration(seconds: 15000));
    
        if (response.statusCode == 200) {
    
         
          return MyItems.fromJson(json.decode(response.body));
        } else {
          throw Exception('Faild to load');
        }
      }

Answer 1

检查条件 snapshot.data.dataa.isEmpty 如果为真，则您的响应为空。

Flutter Snapshot.hasData 总是返回 true

Flutter Snapshot.hasData is always returning true

android

json

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flutter

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