JSON.Net-序列化时对JSON重新排序

Question

I have some JSON similar to this coming over from a call to GoToWebinar's API:

[
   {
      "answer":"The Answer for Question 1",
      "question":"1. This is the Question?"
   },
   {
      "answer":"The Answer for Question 2",
      "question":"2. This is the Question?"
   },
   {
      "answer":"The Answer for Question 7",
      "question":"7. This is the Question?"
   },
   {
      "answer":"The Answer for Question 5",
      "question":"5. This is the Question?"
   },
   {
      "answer":"The Answer for Question 3",
      "question":"3. This is the Question?"
   },
   {
      "answer":"The Answer for Question 8",
      "question":"8. This is the Question?"
   },
   {
      "answer":"The Answer for Question 4",
      "question":"4. This is the Question?"
   },
   {
      "answer":"The Answer for Question 6",
      "question":"6. This is the Question?"
   }
]

It will be serialized using JSON.Net to populate these classes:

public class WebinarQuestions {
    public List<WebinarQuestion> questions { get; set; }
}

public class WebinarQuestion {
    public string answer { get; set; }
    public string question { get; set; }
}

I'd like the WebinarQuestions.questions to be in order. Is there a way to do this without iterating over the JSON?

I don't know why they come over in that order and don't really have any control over them.

Answer 1

As long as the questions all follow a pattern of number. question number. question then the following will sort them after deserialization:

webinarQuestions.questions = webinarQuestions.questions
    .OrderBy(q => int.Parse(q.question.Split('.')[0])).ToList();

It's hacky but it handles question numbers greater than 9.

Answer 2

Any reason you couldn't use Enumerable.OrderBy?

First deserialize the JSON into List<WebinarQuestion> Enumberable object then sort it using OrderBy

questions = questions.OrderBy(x => x.question);

Answer 3

Do this:

string jsonQuestions = @"[
{
  ""answer"":""The Answer for Question 1"",
  ""question"":""1. This is the Question?""
},
{
  ""answer"":""The Answer for Question 2"",
  ""question"":""2. This is the Question?""
},
{
  ""answer"":""The Answer for Question 7"",
  ""question"":""7. This is the Question?""
},
{
  ""answer"":""The Answer for Question 5"",
  ""question"":""5. This is the Question?""
},
{
  ""answer"":""The Answer for Question 3"",
  ""question"":""3. This is the Question?""
},
{
  ""answer"":""The Answer for Question 8"",
  ""question"":""8. This is the Question?""
},
{
  ""answer"":""The Answer for Question 4"",
  ""question"":""4. This is the Question?""
},
{
  ""answer"":""The Answer for Question 6"",
  ""question"":""6. This is the Question?""
}
]";

WebinarQuestions wq = new WebinarQuestions();
wq.questions = JsonConvert.DeserializeObject<List<WebinarQuestion>>(jsonQuestions).OrderBy(x => x.question.Split('.')[0]).ToList();

questions are now in order.

Cheers

EDIT: As pointed out, my original answer would not have worked for more than 9 questions. Now, as others have done and using Split , of course we must do some form of error checking in case the format is wrong.

I have decided to leave this out for brevity.

Answer 4

Make your WebinarQuestion class implement IComparable, this will handle multi digit question numbers:

public class WebinarQuestion : IComparable<WebinarQuestion> {
    public string answer { get; set; }
    public string question { get; set; }

    public int CompareTo(WebinarQuestion other)
    { 
        return QuestionNumber.CompareTo(other.QuestionNumber);
    }

    private int QuestionNumber 
    { 
        get 
        { 
            // Or write more robust parsing if format differs
            return Int32.Parse(question.Split('.')[0]); 
        }
    }
}

Then deserialize to list:

var questions = JsonConvert.DeserializeObject<List<WebinarQuestion>>(json).OrderBy(x => x).ToList();

Edit: if you want to keep your WebinarQuestions class:

public class WebinarQuestions 
{
   public WebinarQuestions(IEnumerable<WebinarQuestion> questions)
   {
       Questions = questions.OrderBy(x => x).ToList();
   }

   public IReadOnlyList<WebinarQuestion> Questions { get; private set; }

   public static WebinarQuestions FromJson(string json)
   {
       var questions = JsonConvert.DeserializeObject<List<WebinarQuestion>>(json);
       return new WebinarQuestions(questions);
   }
}