using System;

using System.Reflection;

public class Program

{

    public static void Main()

    {

        Type custom = typeof(CustomJson<>);

        Type newInstance = custom.MakeGenericType(typeof(TestClass));

        MethodInfo mi = newInstance.GetMethod("Deserialize");

        var res = (TestClass) mi.Invoke(null, new object[] { "{Id: 3}" });

        Console.WriteLine(res.Id);

    }

}

​

public static class CustomJson<T> where T : class, new()

{

    public static T Deserialize(string data)

    {

        try

        {

            if (string.IsNullOrEmpty(data)) 

                return new T();

            return Newtonsoft.Json.JsonConvert.DeserializeObject<T>(data);

        }

        catch (Exception ex)

        {

            Console.WriteLine(ex.Message);

            throw;

        }

    }

}

​

public class TestClass

{

    public int Id { get; set; }

    public TestClass()

    {

    }

}