try
  {
 System.Runtime.Serialization.Json.DataContractJsonSerializer serializer = new System.Runtime.Serialization.Json.DataContractJsonSerializer(list.GetType());
  using (MemoryStream ms = new MemoryStream())
 {
    serializer.WriteObject(ms, list);
    strReturn.msg = Encoding.UTF8.GetString(ms.ToArray());
 }
 }
 catch
 {
    return null;
 }

JavaScriptSerializer serializer = new JavaScriptSerializer();
strReturn.msg = serializer.Serialize(list);

string jsonlist = jsonObject.msg;
JavaScriptSerializer Serializer = new JavaScriptSerializer();
list = Serializer.Deserialize<List<T>>(jsonlist);