Question

I already have the answer for this using silverlight’s System.JSON but specs got changed and now I need to do it in .NET 3.5

here’s the JSON I’m getting

{"SearchResults":[{"PageCount":"1"},
{"SEARCHVAL":"Result","CATEGORY":"Category1","X":"1","Y":"2"},
{"SEARCHVAL":"AnotherResult","CATEGORY":"Category1","X":"2","Y":"2"}]}

and the solution using System.JSON assembly was

var resultList = ((JsonArray)searchResults["SearchResults"])
   .OfType<JsonObject>()
   .Where(o => o.ContainsKey("SEARCHVAL"))
   .Select(o => new SearchResult() { 
       SearchValue = o["SEARCHVALUE"],
       Category = o["CATEGORY"].
       X = o["X"],
       Y = o["Y"]
   }).ToList();

I figure most of the code is similar/exactly the same but I’m not sure about the ContainsKey’s counterpart in JSON.net. I think it’s the Contains() method but I’m not exactly sure how to use it so that I could get the X and Y of the SEARCHVAL.

UPDATE:

so here’s my code to get the JSON stream and parsing:

       ...
       Uri uri = new Uri(url);

       WebClient client = new WebClient();
       ParseJSON(client.OpenRead(uri)); 
    }


    private void ParseJSON(Stream stream)
    {
        if (stream == null)
            return;

        StreamReader reader = new StreamReader(stream);
        JObject searchResult = JObject.Parse(reader.ReadLine());

        string x= searchResult["SearchResults"][0]["SEARCHVAL"]["X"].ToString();
        string y= searchResult["SearchResults"][0]["SEARCHVAL"]["Y"].ToString();

        // use data
        ...

and I’m getting a null exception on string lat = searchresult.... Any clue where I went wrong on using JSON.NET?

Answer 1

Here’s the working solution using JSON.NET:

Getting the json:

        WebClient client = new WebClient();
        using (StreamReader reader = new StreamReader(client.OpenRead(uri)))
        {
            json = reader.ReadToEnd();
        }

Parsing the stream as JObject:

        JObject searchResult = JObject.Parse(json);

        string lat = searchResult["SearchResults"][1]["X"].ToString().Replace("\"","");
        string lon = searchResult["SearchResults"][1]["Y"].ToString().Replace("\"","");

the .Replace() can be disregarded if there are no unnecessary characters included on the parsed string. I was using Json.NET 3.5 so you’ll probably won’t need to do this in the most updated release.