Generics / JSON JavaScriptSerializer C#

Question

Hi

I'm building a winForms app in NET3.5SP1 using VS2008Express. Am trying to deserialize an object using the System.Web.Script.Serialization library.

The error is: Type 'jsonWinForm.Category' is not supported for deserialization of an array.

Cheers!

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Web;
using System.Net;
using System.IO;
using System.Web.Script.Serialization;

namespace jsonWinForm {
    public class Category
    {
        public int categoryid;
        public string name;
        public int serverimageid;
        public DateTime dateuploaded;
        public bool enabled;
    }

    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            using (WebClient client = new WebClient())
            {
                //manipulate request headers (optional)
                client.Headers.Add("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");
                string targetUri = "http://www.davemateer.com/ig/genius/category.php";

                //execute request and read response as string to console
                using (StreamReader reader = new StreamReader(client.OpenRead(targetUri)))
                {
                    string s = reader.ReadToEnd();
                    textBox1.Text = s;

                    Category cat = new Category();
                    JavaScriptSerializer serializer = new JavaScriptSerializer();

                    // this fails with a 
                    //Type 'jsonWinForm.Category' is not supported for deserialization of an array.
                    serializer.Deserialize<Category>(s);
                }
            }
        }
    }
}

Answer 1

I found my error.. should be:

Cheers

            JavaScriptSerializer serializer = new JavaScriptSerializer();

            // create a generic list of categories
            List<Category> listOfCategories = new List<Category>();

            // deserialize as a list of Categories, and put into listOfCategories
            listOfCategories = serializer.Deserialize<List<Category>>(s);

            //iterate through list and display in text box
            foreach (Category item in listOfCategories)
            {
                textBox2.Text += item.categoryid.ToString() + "\r\n";
                textBox2.Text += item.name.ToString() + "\r\n";
                textBox2.Text += item.serverimageid.ToString() + "\r\n";
                textBox2.Text += item.dateuploaded.ToString() + "\r\n";
                textBox2.Text += item.enabled.ToString() + "\r\n";
            }

Answer 2

It's great you found your error. If you are looking for another tool for JSON serialization you might want to try JSON.Net.