using System;

using System.Collections.Generic;

using System.Xml.Serialization;

public class Program

{

    public static void Main()

    {

        List<Tweet> tweets = new List<Tweet>();

        tweets.Add(new Tweet());

        tweets.Add(new Tweet());

        XmlSerializer serializer = new XmlSerializer(typeof(List<Tweet>));

        var stringwriter = new System.IO.StringWriter();

        serializer.Serialize(stringwriter, tweets);

        Console.WriteLine(stringwriter.ToString());

    }

    public class Tweet

    {

        public Tweet()

        {

            Photos = new List<Photo>();

            Photos.Add(new Photo(){

                PhotoHeight = "Foo",

                PhotoUri = "a/random/ur/path",

                PhotoWidth = "923",

                SourcePhotoUri = "a/random/path",

            });

​

            ProfileImage = "a/random/path";

            ScreenName = "FOO";

            Text = "some text";

            TweetId = "1234";

            UserId = "1234";

            Username = "BAR";

        }

​

        public List<Photo> Photos { get; set; }

        public string ProfileImage { get; set; }

        public string ScreenName { get; set; }

        public string Text { get; set; }

        public string TweetId { get; set; }

        public string UserId { get; set; }

        public string Username { get; set; }

    }

    public class Photo

    {

        public string PhotoHeight { get; set; }

        public string PhotoUri { get; set; }

        public string PhotoWidth { get; set; }

        public string SourcePhotoUri { get; set; }

    }

}