Convert Object to JSON String in C#

How do I turn a C# object into a JSON string in .NET?

Please Note

Microsoft recommends that you DO NOT USE JavaScriptSerializer

See the header of the documentation page:

For .NET Framework 4.7.2 and later versions, use the APIs in the System.Text.Json namespace for serialization and deserialization. For earlier versions of .NET Framework, use Newtonsoft.Json.

---

Original answer:

You could use the JavaScriptSerializer class (add reference to System.Web.Extensions):

using System.Web.Script.Serialization;

var json = new JavaScriptSerializer().Serialize(obj);

A full example:

using System;
using System.Web.Script.Serialization;

public class MyDate
{
    public int year;
    public int month;
    public int day;
}

public class Lad
{
    public string firstName;
    public string lastName;
    public MyDate dateOfBirth;
}

class Program
{
    static void Main()
    {
        var obj = new Lad
        {
            firstName = "Markoff",
            lastName = "Chaney",
            dateOfBirth = new MyDate
            {
                year = 1901,
                month = 4,
                day = 30
            }
        };
        var json = new JavaScriptSerializer().Serialize(obj);
        Console.WriteLine(json);
    }
}

Convert C# Object to Json Object

To create correct JSON first you need to prepare appropriate model. It can be something like that:

[DataContract]
public class Customer
{
    [DataMember(Name = "gors_descr")]
    public string ProductDescription { get; set; }

    [DataMember(Name = "b_name_first")]
    public string Fname { get; set; }

    [DataMember(Name = "b_name_last")]
    public string Lname { get; set; }
}

To be able to use Data attributes you will need to choose some other JSON serializer. For example DataContractJsonSerializer or Json.NET(I will use it in this example).

Customer customer = new Customer
{
    ProductDescription = tbDescription.Text,
    Fname = tbFName.Text,
    Lname = tbLName.Text
};

string creditApplicationJson = JsonConvert.SerializeObject(
    new
    {
        jsonCreditApplication = customer
    });

So jsonCreditApplication variable will be:

{
  "jsonCreditApplication": {
    "gors_descr": "Appliances",
    "b_name_first": "Marisol",
    "b_name_last": "Testcase"
  }
}

How to convert an embedded JSON string to a JSON Object in C#

If you know the json response, you can create a model class for it. On VS 2022 you can right click on editor and do paste special Edit --> Paste special --> Paste JSON as Classes. You should get something like below.

public class Model 
{
    public object[] paymentId { get; set; }
    public object[] paymentRequestId { get; set; }
    public object[][][] paymentAmount { get; set; }
    public object[] paymentStatus { get; set; }
    public object[][][] result { get; set; }
}

After using that Model class in your code, your code should look like below

using System.Text.Json;

public Model InquiryPaymentAPI(string id)
{
   
    string paymentInfo = PaymentInquiry.IPayment(id);
    return JsonSerializer.Deserialize<Model>(paymentInfo);

}

How to convert C# class object to json?

I believe you are new to this and want a working sample to kick off the work.

Here you go.

using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
                    
public class Program
{
    public static void Main()
    {
        var o = new UserResponse();
        o.Age = "25";
        o.Gender = "Male";
        o.Message = "Hello";
        o.UserInfo = new User();
        o.UserInfo.Id = 1;
        o.UserInfo.FirstName = "John";
        o.UserInfo.LastName = "Doe";
        o.UserInfo.Balance = 1000M;
        var json = JsonConvert.SerializeObject(o, Formatting.Indented, new JsonSerializerSettings {ContractResolver = new CamelCasePropertyNamesContractResolver()}  );
        Console.WriteLine(json);
    }
}

public class User
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName{ get; set; }
        public decimal Balance { get; set; }
    }

public class UserResponse
    {
        public User UserInfo { get; set; }
        public string Age { get; set; }
        public string Gender { get; set; }
        public string Message { get; set; }
    }

Try it out here...

Sample Code

Converting a string to JSON in C#

First, create your data model. You can use json2sharp, very helpful tool.

public class Item
{
    public int id { get; set; }
    public string title { get; set; }
    public int position_x { get; set; }
    public int position_y { get; set; }
    public int position_z { get; set; }
    public int rotation_x { get; set; }
    public int rotation_y { get; set; }
    public int rotation_z { get; set; }
    public string created { get; set; }
}

Next use Newtonsoft.Json and call deserialize method.

var list = JsonConvert.DeserializeObject<List<Item>>(Yourjson);

Convert object to JSON string in C#

I have used Newtonsoft JSON.NET (Documentation) It allows you to create a class / object, populate the fields, and serialize as JSON.

public class ReturnData 
{
    public int totalCount { get; set; }
    public List<ExceptionReport> reports { get; set; }  
}

public class ExceptionReport
{
    public int reportId { get; set; }
    public string message { get; set; }  
}

string json = JsonConvert.SerializeObject(myReturnData);

Cannot convert JSON string to List of object

This is because you need a container class at the top that has this list of orders as a property inside of it:

public class MyData
{
     public List<FoodItem> Orders { get; set; }
{

var data = JsonConvert.DeserializeObject<MyData>(strProductsInCart);
var items = data.Orders;

Also, make sure you have public properties that match the name in the JSON. They can be Pascal case, too.

Convert JSON String To C# Object

It looks like you're trying to deserialize to a raw object. You could create a Class that represents the object that you're converting to. This would be most useful in cases where you're dealing with larger objects or JSON Strings.

For instance:

  class Test {

      String test; 

      String getTest() { return test; }
      void setTest(String test) { this.test = test; }

  }

Then your deserialization code would be:

   JavaScriptSerializer json_serializer = new JavaScriptSerializer();
   Test routes_list = 
          (Test)json_serializer.DeserializeObject("{ \"test\":\"some data\" }");

More information can be found in this tutorial:
http://www.codeproject.com/Tips/79435/Deserialize-JSON-with-Csharp.aspx

---

Related Topics