将 json 转换为 List<> C#

Question

如何将Json数组转换为列表<> C#

[[{
    "QID": 1,
    "Question": "Question",
    "IsMultipel": 0
},
{
    "QID": 2,
    "Question": "Question",
    "IsMultipel": 1
}],
[{
    "QID": 1,
    "A_ID": 1,
    "Answer": "Answer"
},
{
    "QID": 1,
    "A_ID": 2,
    "Answer": "Answer"
},
{
    "QID": 1,
    "A_ID": 3,
    "Answer": "Answer"
},
{
    "QID": 1,
    "A_ID": 3,
    "Answer": "Answer"
}]]

错误：要修复此错误，请将 JSON 更改为 JSON 对象（例如 {"name":"value"}）或将反序列化类型更改为数组或我正在执行的类型：

List<QuestionAndAnswerNewMarge> _QuestionAndAnswerNewMarge = new List<QuestionAndAnswerNewMarge>();
string str="[[{\"QID\":1,\"Question\":\"Question\",\"IsMultipel\":0},{\"QID\":2,\"Question\":\"Question\",\"IsMultipel\":1}],[{\"QID\":1,\"A_ID\":1,\"Answer\":\"Answer\"},{\"QID\":1,\"A_ID\":2,\"Answer\":\"Answer\"},{\"QID\":1,\"A_ID\":3,\"Answer\":\"Answer\"},{\"QID\":1,\"A_ID\":3,\"Answer\":\"Answer\"}]]";
_QuestionAndAnswerNewMarge = JsonConvert.DeserializeObject<List<QuestionAndAnswerNewMarge>>(str).ToList();

public class QuestionAndAnswerNewMarge
{
    public List<QuestionNew> QuestionNew { get; set; }
    public List<AnswerNew> AnswerNew { get; set; }

}
public class QuestionNew
{

    public string QuestionID { get; set; }
    public string Question { get; set; }
    public string IsMultiple { get; set; }
}
public class AnswerNew
{

    public string QuestionID { get; set; }
    public string AnswerID { get; set; }
    public string Answer { get; set; }
}

Answer 1

JSON 并不真正符合您尝试使用的类型。 您在此处有两个选项，要选择的选项取决于您是否可以更改 JSON 字符串。

如果可以，我建议您手动构建对象，然后将它们序列化。 这会以正确的形式输出 Json 以供使用，您可以设置生成它的人使用该格式。

例如，我稍微调整了您的对象，创建了它的一个实例，重新创建了您的数据，然后对其进行了序列化：

public class QuestionAndAnswerNewMarge
{
    public List<Question> Questions { get; set; }
    public List<Answer> Answers { get; set; }
}

public class Question
{
    public int QuestionID { get; set; }
    public string QuestionText { get; set; }
    public bool IsMultiple { get; set; }
}
public class Answer
{
    public int QuestionID { get; set; }
    public int AnswerID { get; set; }
    public string AnswerText { get; set; }
}

JSON：

{
  "Questions": [
    {
      "QuestionID": 1,
      "QuestionText": "Question",
      "IsMultiple": false
    },
    {
      "QuestionID": 2,
      "QuestionText": "Question",
      "IsMultiple": true
    }
  ],
  "Answers": [
    {
      "QuestionID": 1,
      "AnswerID": 1,
      "AnswerText": "Answer"
    },
    {
      "QuestionID": 1,
      "AnswerID": 2,
      "AnswerText": "Answer"
    },
    {
      "QuestionID": 1,
      "AnswerID": 3,
      "AnswerText": "Answer"
    },
    {
      "QuestionID": 2,
      "AnswerID": 1,
      "AnswerText": "Answer"
    }
  ]
}

如果您从外部源读取 JSON，则使用json2csharp 之类的实用程序生成将使用给定 json 示例进行反序列化的类。

Answer 2

这个解决方案有点脏，但应该适用于您发布的 JSON 字符串

    public void Convert()
    {
        var questionsAnswers = new QuestionsAnswers()
        {
            Answers = new List<Answ>(),
            Questions = new List<Qst>()
        };


        string str = "[[{\"QID\":1,\"Question\":\"Question\",\"IsMultipel\":0},{\"QID\":2,\"Question\":\"Question\",\"IsMultipel\":1}],[{\"QID\":1,\"A_ID\":1,\"Answer\":\"Answer\"},{\"QID\":1,\"A_ID\":2,\"Answer\":\"Answer\"},{\"QID\":1,\"A_ID\":3,\"Answer\":\"Answer\"},{\"QID\":1,\"A_ID\":3,\"Answer\":\"Answer\"}]]";
        var d = JsonConvert.DeserializeObject<dynamic[][]>(str);
        foreach (var objects in d)
        {
            if (objects.All(a => a["A_ID"] == null))
            {
                questionsAnswers.Questions.AddRange(objects.Select(a => new Qst()
                {
                    IsMultipel = a[nameof(Qst.IsMultipel)],
                    Question = a[nameof(Qst.Question)],
                    QID = a[nameof(Qst.QID)]
                }));
            }
            else
            {
                questionsAnswers.Answers.AddRange(objects.Select(a => new Answ()
                {
                    A_ID = a[nameof(Answ.A_ID)],
                    Answer = a[nameof(Answ.Answer)],
                    QID = a[nameof(Answ.QID)]
                }));
            }
        }
    }

    public class QuestionsAnswers
    {
        public List<Qst> Questions { get; set; }
        public List<Answ> Answers { get; set; }
    }

    public class Qst
    {
        public int QID { get; set; }
        public string Question { get; set; }
        public bool IsMultipel { get; set; }
    }

    public class Answ
    {
        public int QID { get; set; }
        public int A_ID { get; set; }
        public string Answer { get; set; }
    }

Answer 3

你可以用这个。 请注意，您需要更新类中的属性名称和类型：

    private void Test()
    {
       QuestionAndAnswerNewMarge q = new QuestionAndAnswerNewMarge();

        JArray ja = JArray.Parse(json);

        var ja1 = JArray.Parse(ja[0].ToString());
        var ja2 = JArray.Parse(ja[1].ToString()); 

        q.QuestionNew = JsonConvert.DeserializeObject<List<QuestionNew>>(ja1.ToString());
        q.AnswerNew = JsonConvert.DeserializeObject<List<AnswerNew>>(ja2.ToString());
    }

    public class QuestionAndAnswerNewMarge
    {
        public List<QuestionNew> QuestionNew { get; set; }
        public List<AnswerNew> AnswerNew { get; set; }
    }
    public class QuestionNew
    {
        public int QID { get; set; }
        public string Question { get; set; }
        public int IsMultiple { get; set; }
    }
    public class AnswerNew
    {
        public string QID { get; set; }
        public string A_ID { get; set; }
        public string Answer { get; set; }
    }