using System;

using Newtonsoft.Json.Linq;

public class Program

{

    public static dynamic AddTermToMatchQuery(JObject match, string fieldName, string fieldValue)

    {

        match.Add(new JProperty(fieldName, fieldValue));

        return match;

    }

    public static void Main()

    {

        dynamic query = new JObject();

        query.match = new JObject();

        query.match = AddTermToMatchQuery(query.match, "fieldName1", "fieldValue1");

        Console.WriteLine(query.ToString());

​

        query.match = AddTermToMatchQuery(query.match, "fieldName2", "fieldValue2");

        Console.WriteLine(query.ToString());

    }

}

​