Deserialize JSON in Silverlight 4 - json

Question

I have a class MyItems in my namespace as
[DataContract]
public class MyItems {
[DataMember]
public int LineNum { get; set; }
[DataMember]
public string ItemCode { get; set; }
[DataMember]
public string Priority { get; set; }
[DataMember]
public string Contact { get; set; }
[DataMember]
public string Message { get; set; }
}
and on an XAML I have a button and in its action listener, I am trying to deserialize the JSON string that is coming from a form and trying to update a DataGrid.
In the first step Inside the action listener, I am trying..
List<MyItems> myItems= JSONHelper.DeserializeToMyItems<myItems>(result);
and result (of type string ) has
{"MyItems":[{"LineNum":"1","ItemCode":"A00001","Contact":"5","Priority":"1","Message":"IBM Infoprint 1312"}, {"LineNum":"2","ItemCode":"A00002","Contact":"5","Priority":"1","Message":"IBM Infoprint 1222"}, {"LineNum":"3","ItemCode":"A00003","Contact":"5","Priority":"1","Message":"IBM Infoprint 1226"}, {"LineNum":"4","ItemCode":"A00004","Contact":"5","Priority":"1","Message":"HP Color Laser Jet 5"}, {"LineNum":"5","ItemCode":"A00005","Contact":"5","Priority":"1","Message":"HP Color Laser Jet 4"}]}
The JSONHelper.DeserializeToMyItems code looks like,
public static List<MyItems> DeserializeToMyItems<MyItems>(string jsonString) { MyItems data = Activator.CreateInstance<MyItems>(); using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(jsonString))) { DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(List<MyItems>)); return (List<MyItems>)serializer.ReadObject(ms); } }
While running, I get an exception at the line serializer.ReadObject(ms)
Unable to cast object of type 'System.Object' to type 'System.Collections.Generic.List`1[ServiceTicket.MyItems]'.
I am not sure how to do a type cast for and I am handling a List of type MyItems. Can anyone help me on this please ?. would be highly appreciated as I am new on Silverlight.
thanks
Denny

Answer 1

Try following, it should resolve your problem.
public class JsonHelper
{
public static T Deserialize<T>(string json)
{
using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(json)))
{
DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(T));
return (T)serializer.ReadObject(ms);
}
}
}
and use the above method like following:
List<MyItems> myItems = JsonHelper.Deserialize<List<MyItems>>(result);
Hope this helps!