Flutter：NoSuchMethodError：類'int'沒有實體方法

我的除錯陳述句正確顯示資料庫，在出現問題并收到錯誤后：未處理的例外：NoSuchMethodError：類'int'沒有實體方法'[]'。當我嘗試顯示在我的應用程式中時，我得到空資料，這是因為我用來存盤值的串列的長度為 0

以下是我的課

class UserDetails extends ChangeNotifier {
  final String? userId;
  final String? mobileno;
  bool? userStatus;
  final String? adhar;
  final String? pan;
  final String? adharno;
  final String? panno;
  UserDetails(
      {this.userId,
      this.mobileno,
      this.userStatus = false,
      this.adhar,
      this.pan,
      this.adharno,
      this.panno});

}

以下是我面臨錯誤的 api

Future<void> getUsers(BuildContext context) async {
    final url = '${PurohitApi().baseUrl}${PurohitApi().users}';
    final List<UserDetails> loadedUsers = [];
    try {
      final client = RetryClient(
        http.Client(),
        retries: 4,
        when: (response) {
          return response.statusCode == 401 ? true : false;
        },
        onRetry: (req, res, retryCount) async {
          //print('retry started $token');

          if (retryCount == 0 && res?.statusCode == 401) {
            var accessToken = await Provider.of<Auth>(context, listen: false)
                .restoreAccessToken();
            // Only this block can run (once) until done

            req.headers['Authorization'] = accessToken;
          }
        },
      );
      var response = await client.get(
        Uri.parse(url),
        headers: {'Authorization': authToken!},
      );

      final extractedData = json.decode(response.body) as Map<String, dynamic>;
      print(extractedData);
      if (extractedData['data'] == null) {
        return;
      }

      extractedData.forEach((userId, userData) {
        print(userId);
        loadedUsers.add(
          UserDetails(
            userId: userData['data']['id'],
            mobileno: userData['data']['mobileno'],
            userStatus: userData['data']['userstatus'],
            adhar: userData['data']['adhar'],
            pan: userData['data']['pan'],
            adharno: userData['data']['adharno'],
            panno: userData['data']['panno'],
          ),
        );
      });
      _users = loadedUsers.reversed.toList();
      //print(users);
      notifyListeners();
    } catch (e) {
      print(e);
    }
  }
}

我面臨 NoSuchMethodError: Class 'int' has no instance method '[]' 嘗試呼叫：來自上面的 api 以下是我的回應

uj5u.com熱心網友回復：

我認為 userId 不應該是字串，它應該是一個整數

    class UserDetails extends ChangeNotifier {
  final int? userId;
  final String? mobileno;
  bool? userStatus;
  final String? adhar;
  final String? pan;
  final String? adharno;
  final String? panno;
  UserDetails(
      {this.userId,
      this.mobileno,
      this.userStatus = false,
      this.adhar,
      this.pan,
      this.adharno,
      this.panno});

}

uj5u.com熱心網友回復：

嘗試在此錯誤中列印您的資料我認為您的資料應該像 userData['id']，

上面的錯誤是你嘗試在回傳的資料中使用 int 作為物件

回傳的 userData 是一個 int

uj5u.com熱心網友回復：

更改此代碼：

extractedData.forEach((userId, userData) {
        print(userId);
        loadedUsers.add(
          UserDetails(
            userId: userData['data']['id'],
            mobileno: userData['data']['mobileno'],
            userStatus: userData['data']['userstatus'],
            adhar: userData['data']['adhar'],
            pan: userData['data']['pan'],
            adharno: userData['data']['adharno'],
            panno: userData['data']['panno'],
          ),
        );
      });

對此：

loadedUsers.add(
      UserDetails(
        userId: extractedData['data']['id'],
        mobileno: extractedData['data']['mobileno'],
        userStatus: extractedData['data']['userstatus'],
        adhar: extractedData['data']['adhar'],
        pan: extractedData['data']['pan'],
        adharno: extractedData['data']['adharno'],
        panno: extractedData['data']['panno'],
      ),
    );

當你呼叫函式時:extractedData是 a的原因： 值不是 map，是 an ，或者。關鍵是一個。當你呼叫這個函式時：map<String,dynamic>forEach(key, value)ObjectdynamicString

value['data]

它會拋出那個錯誤

如果您extractedData是 Map 串列，則可以保留原始代碼，并將提取資料的型別更改為 List ：

final extractedData = json.decode(response.body) as List<Map<String, dynamic>>; 

編輯：您在回應中的資料是地圖串列，因此代碼將是這樣的：

final extractedData = json.decode(response.body) as Map<String,dynamic>;
List<Map<String,dynamic>> data = extractedData['data'];
for (var map in data){
   loadedUsers.add(
      UserDetails(
        userId: map['id'],
        mobileno: map['mobileno'],
        userStatus: map['userstatus'],
        adhar: map['adhar'],
        pan: map['pan'],
        adharno: map['adharno'],
        panno: map['panno'],
      ),
    );
}

標籤：扑api

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