Parsing json objects

Question

I'm having trouble understanding how to parse JSON string into c# objects with Visual .NET. The task is very easy, but I'm still lost... I get this string:

{"single_token":"842269070","username":"example123","version":1.1}

And this is the code where I try to desterilize:

namespace _SampleProject
{
    public partial class Downloader : Form
    {
        public Downloader(string url, bool showTags = false)
        {
            InitializeComponent();
            WebClient client = new WebClient();
            string jsonURL = "http://localhost/jev";   
            source = client.DownloadString(jsonURL);
            richTextBox1.Text = source;
            JavaScriptSerializer parser = new JavaScriptSerializer();
            parser.Deserialize<???>(source);
        }

I don't know what to put between the '<' and '>', and from what I've read online I have to create a new class for it..? Also, how do I get the output? An example would be helpful!

Answer 1

Create a new class that your JSON can be deserialized into such as:

public class UserInfo
{
    public string single_token { get; set; }
    public string username { get; set; }
    public string version { get; set; }
}

public partial class Downloader : Form
{
    public Downloader(string url, bool showTags = false)
    {
        InitializeComponent();
        WebClient client = new WebClient();
        string jsonURL = "http://localhost/jev";
        source = client.DownloadString(jsonURL);
        richTextBox1.Text = source;
        JavaScriptSerializer parser = new JavaScriptSerializer();
        var info = parser.Deserialize<UserInfo>(source);

        // use deserialized info object
    }
}

Answer 2

If you're using .NET 4 - use the dynamic datatype.

http://msdn.microsoft.com/en-us/library/dd264736.aspx

string json = "{ single_token:'842269070', username: 'example123', version:1.1}";

     JavaScriptSerializer jss = new JavaScriptSerializer();

     dynamic obj = jss.Deserialize<dynamic>(json);

     Response.Write(obj["single_token"]);
     Response.Write(obj["username"]);
     Response.Write(obj["version"]); 

Answer 3

The usual way would be create a class (or a set of classes, for more complex JSON strings) that describes the object you want to deserialize and use that as the generic parameter.

Another option is to deserialize the JSON into a Dictionary<string, object>:

parser.Deserialize<Dictionary<string, object>>(source);

This way, you can access the data, but I wouldn't suggest you to do this unless you have to.

Answer 4

dynamic data = JObject.Parse(jsString);
var value= data["value"];

Answer 5

You need a Class that match with the JSON you are getting and it will return a new object of that class with the values populated.

Answer 6

Yes, you need a new class with properties that will match your JSON.

MyNewClass result = parser.Deserialize<MyNewClass>(source);