flutter - 接收方:空E/flutter(4835):尝试调用:[] (“Data”)

Question

我正在尝试在flutter变量中获取JSON值，但它显示

[ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: NoSuchMethodError: Class 'int' has no instance method '[]'.
E/flutter ( 4835): Receiver: 1
E/flutter ( 4835): Tried calling: []("Data")

是什么原因导致我错了
future 功能代码:

 Future<void> saveData(dynamic jsonOfUser) async {
    setState(() {
      isUploading = true;
    });
    await Future.delayed(Duration(seconds: MyConstant.VAL_SECONDS), () {});
    return post(
      MyConstant.URL_USER_INSERT_LOGIN,
      body: jsonOfUser,
    ).then((onRecievedResponse) {
      var recievedValue = json.decode(onRecievedResponse.body);
      status = recievedValue["status"];
      userData = recievedValue[1]["Data"][5]["type"];

      print(userData);
      userInputValidation();

      print(recievedValue);

      setState(() {
        isUploading = false;
      });
      return null;
    });
  }

我想从数据中获取类型的值

{
"status": 1,
"data": [
{
"id": "304",
"name": "Name1",
"username": "User Name1",
"password": "Pass1",
"type": "1"
}
]

这是Http调用的类:

class MyConstant {
  static const String BASE_URL_ = 'http://95b5bc9c992c.ngrok.io/';

  static const String URL_API = BASE_URL_ + 'fyp/';
  static const String URL_Symptoms = 'http://531c3f6becb9.ngrok.io/?symptoms=';

  static const String URL_USER_INSERT = URL_API + 'user_signup.php';
  static const String URL_USER_INSERT_LOGIN = URL_API + 'user_login.php';
  static const String URL_USER_Symptoms = URL_API + 'user_symptoms.php';
  static const int VAL_SECONDS = 0;
}

Answer 1

试试这个recievedValue["data"][0]["type"]