Deserializing JSON array into strongly typed .NET object

Question

When I can call the 3rd party api and get back a single class worth of data everything deserialises fine using this code

TheUser me = jsonSerializer.Deseria         


        

Answer 1

I suspect the problem is because the json represents an object with the list of users as a property. Try deserializing to something like:

public class UsersResponse
{
    public List<User> Data { get; set; }
}

Answer 2

Json.NET - Documentation

http://james.newtonking.com/json/help/index.html?topic=html/SelectToken.htm

Interpretation for the author

var o = JObject.Parse(response);
var a = o.SelectToken("data").Select(jt => jt.ToObject<TheUser>()).ToList();

Answer 3

I like this approach, it is visual for me.

using (var webClient = new WebClient())
    {
          var response = webClient.DownloadString(url);
          JObject result = JObject.Parse(response);
          var users = result.SelectToken("data");   
          List<User> userList = JsonConvert.DeserializeObject<List<User>>(users.ToString());
    }

Answer 4

Afer looking at the source, for WP7 Hammock doesn't actually use Json.Net for JSON parsing. Instead it uses it's own parser which doesn't cope with custom types very well.

If using Json.Net directly it is possible to deserialize to a strongly typed collection inside a wrapper object.

var response = @"
    {
        ""data"": [
            {
                ""name"": ""A Jones"",
                ""id"": ""500015763""
            },
            {
                ""name"": ""B Smith"",
                ""id"": ""504986213""
            },
            {
                ""name"": ""C Brown"",
                ""id"": ""509034361""
            }
        ]
    }
";

var des = (MyClass)Newtonsoft.Json.JsonConvert.DeserializeObject(response, typeof(MyClass));

return des.data.Count.ToString();

and with:

public class MyClass
{
    public List<User> data { get; set; }
}

public class User
{
    public string name { get; set; }
    public string id { get; set; }
}

Having to create the extra object with the data property is annoying but that's a consequence of the way the JSON formatted object is constructed.

Documentation: Serializing and Deserializing JSON

Answer 5

Pat, the json structure looks very familiar to a problem i described here - The answer for me was to treat the json representation as a Dictionary<TKey, TValue>, even though there was only 1 entry.

If I am correct your key is of type string and the value of a List<T> where T represents the class 'TheUser'

HTH

PS - if you want better serialisation perf check out using Silverlight Serializer, you'll need to build a WP7 version, Shameless plug - I wrote a blog post about this

Answer 6

This worked for me for deserializing JSON into an array of objects:

List<TheUser> friends = JsonConvert.DeserializeObject<List<TheUser>>(response);