JsonUtility.FromJson 创建列表<对象> [重复]答案

【问题标题】：JsonUtility.FromJson Create List<Object> [duplicate]JsonUtility.FromJson 创建列表<对象> [重复]
【发布时间】：2016-05-05 20:20:47
【问题描述】：

我在将 json 字符串转换为 c# 列表时遇到了一些问题！

这是我从服务器获取的 JSON。

[
{"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}
]

在我的 C# 程序中，我尝试使用此函数将我的 json 字符串转换为可用的对象

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;
    }

这里出错了

ArgumentException：JSON 必须表示对象类型。

我环顾四周，没有发现任何可行的方法，尝试了 2-3 解决方案，甚至尝试编辑了创建 JSON 字符串的我的 php web 服务。

我的课程是这样的

    /* 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;
    }

}

感谢您观看这篇长文！

【问题讨论】：

标签： c# json unity3d

【解决方案1】：

Unity 的新 Json API 不支持 Json array，而这正是您的问题所在。有办法做到这一点，但重新发布是一个漫长的过程。只需阅读如何做到这一点here。您正在寻找的是第二个解决方案，上面写着“2. MULTIPLE DATA(ARRAY JSON)。”

【讨论】：

非常感谢，我会看看这个解决方案！
它就像一个魅力！谢谢！

【解决方案2】：

创建一个类和另一个类保存它的列表对我有用。

[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);

从一个列表，转换成 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"}]}

注意：“list”和 questionList.list 应该同名。

【讨论】：