颤振快照.hasData总是返回true

Question

我需要从服务器获取数据，有时数据可以是空的，logcat的响应是数据snapshot.data返回我的模型Instance of 'MyItems'的实例，当数据不可用时服务器的响应是

{
"data": []
}

问题是snapshot.hasData总是为空响应返回true，我已经测试了快照。数据== null仍然是正确的

模型类

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,

};
}

My Future api call

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snapshot.data.dataa.isEmpty条件，如果为真，则为空响应。