Post List <int> in http Flutter - json

Question

I want to send a data like this :
{
"ad_title": "test",
"year": "2019",
"class": "Highline",
"files": [ 212]
}
To api in flutter. I tried to do that
var data = {
"year": selectedYear,
"class": _classController.text.toString(),
"files": json.encode(carfilesids),
};
final response = await http.post(url, body: data,headers:
{'Accept': 'application/json'});
However there's no errors in run time and when I print the value of json.encoder.convert(carfilesids) it gives me List, I got a response status code of 422 and it tells me " {"message":"The given data was invalid.","errors":{"files":["The files must be an array."]}} ". I also tried to json.encode the whole data but it goes wrong with the other data attributes.

Answer 1

You must use jsonEncode on your map, or else the http package will treat it as form data.
From the documentation:
If body is a Map, it's encoded as form fields using encoding. The content-type of the request will be set to "application/x-www-form-urlencoded"; this cannot be overridden.

Answer 2

final response = await http.post(url,
body: {
"ad_title": "test",
"year": "2019",
"class": "Highline",
"files": [ 212 ]
},
headers: {
'Accept': 'application/json'
}
);