Fetching json array, null pointer refrence exception - json

Question

{"names":["name1","name2","name3","name4"]}
I need to fetch this and show them in a list. What I am doing is
public class brand
{ public string Name
{ get; set; }
}
public class brands
{ public list<brand> Names
{ get; set; }
}
public partial class MainPage : PhoneApplicationPage
{
// Constructor
public MainPage()
{
InitializeComponent();
getdata();
}
private void getdata()
{
string uri = "URL";
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(new Uri(uri));
req.BeginGetResponse(new AsyncCallback(show), req);
}
private void show(IAsyncResult asynchronousResult)
{
HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
StreamReader stream1 = new StreamReader(response.GetResponseStream());
string s1 = stream1.ReadToEnd();
var ser = new DataContractJsonSerializer(typeof(brands));
var stream = new MemoryStream(Encoding.Unicode.GetBytes(s1));
var bb = (brands)ser.ReadObject(stream);
foreach (var ev in bb.Names)
{
textBlock1.Text = ev.Name.ToString();
}
}
This I made after reading blog posts. I am getting NullReferenceException.
Please tell me where I am doing wrong or alternative way to do the same.

Answer 1

First learn how to parse your JSON data. Consider this as a json string.
String jsonData = #"{""names"":[""name1"",""name2"",""name3"",""name4""]}";
var brands = JsonConvert.DeserializeObject<Brands>(jsonData);
foreach (var item in brands.names)
{
Console.WriteLine(item);
}
Where your Brands class is like this
public class Brands
{
public List<string> names { get; set; }
}
This above code explains how to parse your json data. Now, coming to fetching your json data from web service, as your request is not a POST request (it appears to be get from your code), you can use a simple WebCleint.
void getData()
{
WebClient webClient = new WebClient();
webClient.DownloadStringCompleted += new DownloadStringCompletedEventHandler(webClient_DownloadStringCompleted);
webClient.DownloadStringAsync(new Uri("url"));
}
void wc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
var brands = JsonConvert.DeserializeObject<Brands>(e.Result);
foreach (var item in brands.names)
{
Console.WriteLine(item);
}
}
Check this blog for any other doubts : Parsing JSON in a Windows Phone Application