Unhandled Exception: type 'String' is not a subtype of type 'Map<String, dynamic> flutter

Question

Is there any way to fix this error i am storing in shared preferences as a map but retrieving is a problem is there any way to fix this error. Here is the output of the code

{
    "fname": "lsbsb",
    "role": "Architect",
    "lname": "bxbdbeb",
    "work_email": "lemu12@gmail.com ",
    "password": "1234",
    "location": "bsbsbs",
    "phonenumber": "9181828",
    "address": "xbbdbsb",
    "zip": "nsbeb",
    "country": "zbbdbdb",
    "id": 3
}

Encoding part of the code

if (response.statusCode == 200) {      
      print(response.body);
      prefs = await SharedPreferences.getInstance();
      String encodedMap = json.encode(response.body);
      prefs.setString("UserData", encodedMap);
    }

Then the decoding part

  getPrefs(BuildContext context) async {
    var prefs = await SharedPreferences.getInstance();
    final encodedMap = prefs.getString('UserData');
    Map<String, dynamic> user = jsonDecode(encodedMap!);}

Answer 1

Hello I tried your code and works well for me. The only difference I used jsonEncode instead json.encode. If persist try debug the response in the decoding part, try final user = jsonDecode(encodedMap!) and see if the response is a Map or a String

final data = {
          "fname": "lsbsb",
          "role": "Architect",
          "lname": "bxbdbeb",
          "work_email": "lemu12@gmail.com ",
          "password": "1234",
          "location": "bsbsbs",
          "phonenumber": "9181828",
          "address": "xbbdbsb",
          "zip": "nsbeb",
          "country": "zbbdbdb",
          "id": 3
        };

        final prefs = await SharedPreferences.getInstance();
        String encodedMap = jsonEncode(data);
        await prefs.setString("UserData", encodedMap);

        //  Get response
        final dataEncoded = prefs.getString('UserData');
        Map<String, dynamic> user = jsonDecode(dataEncoded ?? '');
        print(user);

Answer 2

This is happening because you are trying to encode the response body. There should be json.decode(response.body).

You are trying to encode already string object to string!