我正在 Flutter 中開發一個應用程式。我的Future面臨問題。來自未來構建器中的未來資料給出錯誤模型沒有吸氣劑長度，它也作為Instance of TopicsModel資料顯示在列印中。
請幫忙。
下面是我的代碼：
主題模型.dart
class TopicsModel {
List<Topics> topics = [];
TopicsModel();
TopicsModel.fromJson(Map<String, dynamic> jsonMap) {
try {
topics = jsonMap['topics'] != null
? parseTopicsAttributes(jsonMap['topics'])
: [];
print(jsonMap['topics']);
} catch (e) {
topics = [];
}
}
static List<Topics> parseTopicsAttributes(attributesJson) {
List list = attributesJson;
print("in list making");
List<Topics> attrList = list.map((data) => Topics.fromJson(data)).toList();
return attrList;
}
}
class Topics {
int id;
String name;
Topics.fromJson(Map<String, dynamic> json) {
print("hash problem");
print(json);
id = json["sound_id"];
name = json["title"];
}
}
未來
Future<TopicsModel> getFavTopics() async {
print("get_only_fav_topics");
print(userRepo.currentUser.value.userId.toString());
print(userRepo.currentUser.value.token);
Uri uri = Helper.getUri('get_only_fav_topics');
uri = uri.replace(queryParameters: {
'user_id': userRepo.currentUser.value.userId == null
? "0"
: userRepo.currentUser.value.userId.toString(),
"app_token": userRepo.currentUser.value.token
});
try {
Map<String, String> headers = {
'Content-Type': 'application/json; charset=UTF-8',
'USER': '${GlobalConfiguration().get('api_user')}',
'KEY': '${GlobalConfiguration().get('api_key')}',
};
var response = await http.get(uri, headers: headers);
if (response.statusCode == 200) {
var jsonData = json.decode(response.body);
if (jsonData['status'] == 'success') {
print("topicssssssssssssssss");
print(jsonData);
return (json).decode(response.body)['data'];
}
}
} catch (e) {
print(e.toString());
}
}
展望未來建設者
child: FutureBuilder<TopicsModel>(
builder: (context, projectSnap) {
print("Projeccct");
print(projectSnap);
if (projectSnap.connectionState ==
ConnectionState.none &&
projectSnap.hasData == null) {
//print('project snapshot data is: ${projectSnap.data}');
return Container();
}
if (projectSnap.connectionState ==
ConnectionState.done &&
projectSnap.hasData) {
print("ind one");
print(projectSnap.data.toString());
return ListView.builder(
scrollDirection: Axis.horizontal,
shrinkWrap: true,
itemCount: projectSnap.data.length,
itemBuilder: (context, index) {
return new ChoiceChip(
pressElevation: 0.0,
selectedColor: settingRepo
.setting
.value
.buttonColor,
selected: false,
backgroundColor: Colors.white,
label: Text(projectSnap
.data[index].name));
},
);
} else {
return Container();
}
},
future: getFavTopics(),
)
杰森回應：
{
"status":"success",
"data":{
"topics":[
{
"fav_id":1,
"sound_id":3321,
"user_id":0,
"created_at":"2021-05-07 10":"01":25,
"title":"title 1",
"sound_name":1620381685.mp3,
"cat_id":4,
"parent_id":0,
"duration":30,
"album":"Album 1",
"artist":,
"tags":null,
"used_times":0,
"deleted":0,
"active":1,
"image":fLNu9mZDAAHNYJcdNK6YRJPvPVxmpzPidHZRhhW5.jpg
},
{
"fav_id":41,
"sound_id":3319,
"user_id":0,
"created_at":"2021-05-07 09":"58":52,
"title":"Title 2",
"sound_name":1620381532.mp3,
"cat_id":2,
"parent_id":0,
"duration":15,
"album":"Album 1",
"artist":,
"tags":null,
"used_times":0,
"deleted":0,
"active":1,
"image":54PKLMXikjx0KDCHQSL8uep42oXxzF4qtvI7VpHE.jpg
}
]
}
}
uj5u.com熱心網友回復：
您需要通用
將此更改
child: FutureBuilder(
為
child: FutureBuilder<List<Topics>>(
uj5u.com熱心網友回復：
你用異步呼叫你的未來
FutureBuilder<List<Topics>>(
future: getFavTopics(),
builder: (context, AsyncSnapshot<List<Topics>> projectSnap) {
有關更多資訊，您可以閱讀本文何時應該使用 FutureBuilder？
uj5u.com熱心網友回復：
您沒有將 Model 類與您的 FutureBuilder 連接起來。資料將來自模型，因此呼叫模型類，如：
FutureBuilder<Topics>()
轉載請註明出處，本文鏈接：https://www.uj5u.com/ruanti/359637.html