JsonUtility.FromJson Create List

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!

score 9 · Accepted Answer · edited May 23 '17 at 10:31

9

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)."

edited May 23 '17 at 10:31

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answered May 05 '16 at 21:51

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Many Thanks i'll look in the this solution! – Måns Dahlström May 06 '16 at 08:03
It worked like a charm! Thank you! – Måns Dahlström May 06 '16 at 08:29

PJ3 · Answer 2 · 2017-01-06T05:36:20.653

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.

2 Answers2