How can I convert a JSON object to a custom C# object?

Question

How can I populate my C# object with the JSON object passed via AJAX?

This is the JSON object passed to a C# web method from the page using JSON.stringify:

{
    "user": {
        "name": "asdf",
        "teamname": "b",
        "email": "c",
        "players": ["1", "2"]
    }
}

The C# web method that receives the JSON object:

[WebMethod]
public static void SaveTeam(Object user)
{

}

The C# class that represents the object structure of JSON Object passed in to the web method

public class User
{
    public string name { get; set; }
    public string teamname { get; set; }
    public string email { get; set; }
    public Array players { get; set; }
}

Answer 1

This one depends on the Newtonsoft NuGet package, which is faster than the default serializer.

if we have a class then we can use the below code:

Mycustomclassname oMycustomclassname = Newtonsoft.Json.JsonConvert.DeserializeObject<Mycustomclassname>(jsonString);

if no class then use dynamic:

var oMycustomclassname = Newtonsoft.Json.JsonConvert.DeserializeObject<dynamic>(jsonString);

Answer 2

A good way to use JSON in C# is with JSON.NET

Quick Starts & API Documentation from JSON.NET - Official site help you work with it.

An example of how to use it:

public class User
{
    public User(string json)
    {
        JObject jObject = JObject.Parse(json);
        JToken jUser = jObject["user"];
        name = (string) jUser["name"];
        teamname = (string) jUser["teamname"];
        email = (string) jUser["email"];
        players = jUser["players"].ToArray();
    }

    public string name { get; set; }
    public string teamname { get; set; }
    public string email { get; set; }
    public Array players { get; set; }
}

// Use
private void Run()
{
    string json = @"{""user"":{""name"":""asdf"",""teamname"":""b"",""email"":""c"",""players"":[""1"",""2""]}}";
    User user = new User(json);

    Console.WriteLine("Name : " + user.name);
    Console.WriteLine("Teamname : " + user.teamname);
    Console.WriteLine("Email : " + user.email);
    Console.WriteLine("Players:");

    foreach (var player in user.players)
        Console.WriteLine(player);
 }

Answer 3

To keep your options open, if you're using .NET 3.5 or later, here is a wrapped up example you can use straight from the framework using Generics. As others have mentioned, if it's not just simple objects you should really use JSON.net.

public static string Serialize<T>(T obj)
{
    DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
    MemoryStream ms = new MemoryStream();
    serializer.WriteObject(ms, obj);
    string retVal = Encoding.UTF8.GetString(ms.ToArray());
    return retVal;
}

public static T Deserialize<T>(string json)
{
    T obj = Activator.CreateInstance<T>();
    MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json));
    DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
    obj = (T)serializer.ReadObject(ms);
    ms.Close();
    return obj;
}

You'll need:

using System.Runtime.Serialization;

using System.Runtime.Serialization.Json;

Answer 4

Given your code sample, you shouldn't need to do anything else.

If you pass that JSON string to your web method, it will automatically parse the JSON string and create a populated User object as the parameter for your SaveTeam method.

Generally though, you can use the JavascriptSerializer class as below, or for more flexibility, use any of the various Json frameworks out there (Jayrock JSON is a good one) for easy JSON manipulation.

 JavaScriptSerializer jss= new JavaScriptSerializer();
 User user = jss.Deserialize<User>(jsonResponse); 

Answer 5

Another really simple solution is using the library Newtonsoft.Json:

User user = JsonConvert.DeserializeObject<User>(jsonString);

Answer 6

The following 2 examples make use of either

1. JavaScriptSerializer under System.Web.Script.Serialization Or
2. Json.Decode under System.Web.Helpers

---

Example 1: using System.Web.Script.Serialization

using Microsoft.VisualStudio.TestTools.UnitTesting;
using System.Web.Script.Serialization;

namespace Tests
{
    [TestClass]
    public class JsonTests
    {
        [TestMethod]
        public void Test()
        {
            var json = "{\"user\":{\"name\":\"asdf\",\"teamname\":\"b\",\"email\":\"c\",\"players\":[\"1\",\"2\"]}}";
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            dynamic jsonObject = serializer.Deserialize<dynamic>(json);

            dynamic x = jsonObject["user"]; // result is Dictionary<string,object> user with fields name, teamname, email and players with their values
            x = jsonObject["user"]["name"]; // result is asdf
            x = jsonObject["user"]["players"]; // result is object[] players with its values
        }
    }
}

Usage: JSON object to Custom C# object

using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using System.Web.Script.Serialization;
using System.Linq;

namespace Tests
{
    [TestClass]
    public class JsonTests
    {
        [TestMethod]
        public void TestJavaScriptSerializer()
        {
            var json = "{\"user\":{\"name\":\"asdf\",\"teamname\":\"b\",\"email\":\"c\",\"players\":[\"1\",\"2\"]}}";
            User user = new User(json);
            Console.WriteLine("Name : " + user.name);
            Console.WriteLine("Teamname : " + user.teamname);
            Console.WriteLine("Email : " + user.email);
            Console.WriteLine("Players:");
            foreach (var player in user.players)
                Console.WriteLine(player);
        }
    }

    public class User {
        public User(string json) {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            var jsonObject = serializer.Deserialize<dynamic>(json);
            name = (string)jsonObject["user"]["name"];
            teamname = (string)jsonObject["user"]["teamname"];
            email = (string)jsonObject["user"]["email"];
            players = jsonObject["user"]["players"];
        }

        public string name { get; set; }
        public string teamname { get; set; }
        public string email { get; set; }
        public Array players { get; set; }
    }
}

---

Example 2: using System.Web.Helpers

using Microsoft.VisualStudio.TestTools.UnitTesting;
using System.Web.Helpers;

namespace Tests
{
    [TestClass]
    public class JsonTests
    {
        [TestMethod]
        public void TestJsonDecode()
        {
            var json = "{\"user\":{\"name\":\"asdf\",\"teamname\":\"b\",\"email\":\"c\",\"players\":[\"1\",\"2\"]}}";
            dynamic jsonObject = Json.Decode(json);

            dynamic x = jsonObject.user; // result is dynamic json object user with fields name, teamname, email and players with their values
            x = jsonObject.user.name; // result is asdf
            x = jsonObject.user.players; // result is dynamic json array players with its values
        }
    }
}

Usage: JSON object to Custom C# object

using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using System.Web.Helpers;
using System.Linq;

namespace Tests
{
    [TestClass]
    public class JsonTests
    {
        [TestMethod]
        public void TestJsonDecode()
        {
            var json = "{\"user\":{\"name\":\"asdf\",\"teamname\":\"b\",\"email\":\"c\",\"players\":[\"1\",\"2\"]}}";
            User user = new User(json);
            Console.WriteLine("Name : " + user.name);
            Console.WriteLine("Teamname : " + user.teamname);
            Console.WriteLine("Email : " + user.email);
            Console.WriteLine("Players:");
            foreach (var player in user.players)
                Console.WriteLine(player);
        }
    }

    public class User {
        public User(string json) {
            var jsonObject = Json.Decode(json);
            name = (string)jsonObject.user.name;
            teamname = (string)jsonObject.user.teamname;
            email = (string)jsonObject.user.email;
            players = (DynamicJsonArray) jsonObject.user.players;
        }

        public string name { get; set; }
        public string teamname { get; set; }
        public string email { get; set; }
        public Array players { get; set; }
    }
}

This code requires adding System.Web.Helpers namespace found in,

%ProgramFiles%\Microsoft ASP.NET\ASP.NET Web Pages{VERSION}\Assemblies\System.Web.Helpers.dll

Or

%ProgramFiles(x86)%\Microsoft ASP.NET\ASP.NET Web Pages{VERSION}\Assemblies\System.Web.Helpers.dll

Answer 7

public static class Utilities
{
    public static T Deserialize<T>(string jsonString)
    {
        using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(jsonString)))
        {    
            DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(T));
            return (T)serializer.ReadObject(ms);
        }
    }
}

More information go to following link http://ishareidea.blogspot.in/2012/05/json-conversion.html

About DataContractJsonSerializer Class you can read here.

Answer 8

Using JavaScriptSerializer() is less strict than the generic solution offered :

public static T Deserialize<T>(string json)

That might come handy when passing json to the server that does not match exactly the Object definition you are trying to convert to.

Answer 9

Performance-wise, I found the ServiceStack's serializer a bit faster than then others. It's JsonSerializer class in ServiceStack.Text namespace.

https://github.com/ServiceStack/ServiceStack.Text

ServiceStack is available through NuGet package: https://www.nuget.org/packages/ServiceStack/

Answer 10

JSON.Net is your best bet but, depending on the shape of the objects and whether there are circular dependencies, you could use JavaScriptSerializer or DataContractSerializer.

Answer 11

The JSON C# class generator on codeplex generates classes which work well with NewtonSoftJS.

Answer 12

JavaScript Serializer: requires using System.Web.Script.Serialization;

public class JavaScriptSerializerDeSerializer<T>
{
    private readonly JavaScriptSerializer serializer;

    public JavaScriptSerializerDeSerializer()
    {
        this.serializer = new JavaScriptSerializer();
    }

    public string Serialize(T t)
    {
        return this.serializer.Serialize(t);
    }

    public T Deseralize(string stringObject)
    {
        return this.serializer.Deserialize<T>(stringObject);
    }
}

Data Contract Serializer: requires using System.Runtime.Serialization.Json; - The generic type T should be serializable more on Data Contract

public class JsonSerializerDeserializer<T> where T : class
{
    private readonly DataContractJsonSerializer jsonSerializer;

    public JsonSerializerDeserializer()
    {
        this.jsonSerializer = new DataContractJsonSerializer(typeof(T));
    }

    public string Serialize(T t)
    {
        using (var memoryStream = new MemoryStream())
        {
            this.jsonSerializer.WriteObject(memoryStream, t);
            memoryStream.Position = 0;
            using (var sr = new StreamReader(memoryStream))
            {
                return sr.ReadToEnd();
            }
        }
    }

    public T Deserialize(string objectString)
    {
        using (var ms = new MemoryStream(System.Text.ASCIIEncoding.ASCII.GetBytes((objectString))))
        {
            return (T)this.jsonSerializer.ReadObject(ms);
        }
    }
}

Answer 13

Rather than sending as just an object, create a public class of properties that is accessible and send the data to the Webmethod.

[WebMethod]
public static void SaveTeam(useSomeClassHere user)
{
}

Use the same parameters names in the Ajax call to send the data.