JsonUtility.FromJson Create List<Object> [duplicate]

Question

I have some problems with converting a json string into a c# List!

This is my JSON that i get from form a server.

[
{"roundid":1,"coins":700,"created":"2016-03-16 11:13:26","duration":198,"score":765230},
{"roundid":3,"coins":330,"created":"2016-03-16 11:13:56","duration":123,"score":425726},
{"roundid":4,"coins":657,"created":"2016-03-16 11:21:23","duration":432,"score":75384},
{"roundid":8,"coins":980,"created":"2016-03-16 11:23:19","duration":271,"score":827200}
]

In my C# program i then try to transform my json string into useable objects using with this function

public List<Round> getPlayerRounds(string username)
    {
        string url = BaseURL + "op=findUserRounds&username=" + username;
        var json = new WebClient().DownloadString(url);
        RoundDataList rounds = JsonUtility.FromJson<RoundDataList>(json);

        List<Round> playerRounds = new List<Round>();
        //for (var i = 0; i < rounds.roundList.Count; i++)
        for (var i = 0; i < rounds.roundList.Length; i++)
        {
            RoundData rd = rounds.roundList[i];
            Round r = rd.getRound();
            playerRounds.Add(r);
        }
        return playerRounds;
    }

Here i get error

ArgumentException: JSON must represent an object type.

I've looked around and haven't found anything that works, Tried 2-3 solution even tried edited my php webservice that creates the JSON string.

My Classes looks like this

    /* This is previus atempt to solve the issue
    [Serializable]
    public class RoundDataList
    {
        public List<RoundData> roundList;
    }
    */
    [Serializable]
    public class RoundDataList
    {
        public RoundData[] roundList;
    }
[Serializable]
public class RoundData
{
    public int roundid;
    public int coins;
    public DateTime created;
    public int duration;
    public int score;


    public Round getRound()
    {
        Round r = new Round();
        r.Roundid = roundid;
        r.Coins = coins;
        r.Created = created;
        r.Duration = duration;
        r.Score = score;
        return r;
    }

}

Thank for looking at this long post!

Answer 1

Unity's new Json API does not support Json array and that is exactly what your problem is. There is a way to do it but it is a long process to repost again. Just read how to do it here.What you are looking for is the second solution that says "2. MULTIPLE DATA(ARRAY JSON)."

Answer 2

Creating a class and another class holding list of it works for me.

[Serializable]
public class Questions
{
    public string id;
    public string question;
    public string answer1;
    public string answer2;
}

[Serializable]
public class QuestionList
{
    public List<Questions> list;
}

//and

var jstring = "{\"list\":[{\"id\":\"1\",\"question\":\"lorem Ipsome \",\"answer1\":\"yes\",\"answer2\":\"no\"},{\"id\":\"2\",\"question\":\"lorem Ipsome Sit dore iman\",\"answer1\":\"si\",\"answer2\":\"ne\"}]}";

var result = JsonUtility.FromJson<QuestionList>(jstring);

From a list, Convert to JSON

List<Questions> questionlist = new List<Questions>();
questionlist.Add(new Questions()
{
    answer1 = "yes",
    answer2 = "no",
    id = "1",
    question = "lorem Ipsome "
});

questionlist.Add(new Questions()
{
    answer1 = "si",
    answer2 = "ne",
    id = "2",
    question = "lorem Ipsome Sit dore iman"
});

var ql = new QuestionList();
ql.list = questionlist;


var result = JsonUtility.ToJson(ql);  

//this gives
{"list":[{"id":"1","question":"lorem Ipsome ","answer1":"yes","answer2":"no"},{"id":"2","question":"lorem Ipsome Sit dore iman","answer1":"si","answer2":"ne"}]}

Note: "list" and questionList.list should be in same name.