C obtains JSON format data asynchronously from the web address

1  Start visiting

public static void StartAccessingURL(string url,int index)
        {
            try
            {
                HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);

                webRequest.Method = "Get";
                webRequest.ContentType = "application/json";
                webRequest.Headers.Add("Authorization", "MzQ1");  //token

                
                webRequest.BeginGetResponse(new AsyncCallback(OnOneResponse), webRequest);
            }
            catch(Exception ex)
            {
                Log.LogHelper.Error("StartAccessingURL() " + ex.Message);
            }
        }

2  Callback function

public static void OnOneResponse(IAsyncResult ar)
        {
            try
            {
                WebRequest wrq = (WebRequest)ar.AsyncState;
                WebResponse wrs = wrq.EndGetResponse(ar);

                HttpWebResponse httpWebResponse = (HttpWebResponse)wrs;
                StreamReader reader = new StreamReader(httpWebResponse.GetResponseStream(), Encoding.UTF8);
                string data = reader.ReadToEnd();
                reader.Close();
                httpWebResponse.Close();

                getData(data);
            }
            catch(Exception e)
            {
                Log.LogHelper.Error("OnOneResponse" + e.Message);
            }
        }

3  Get data

public static void getData(string str)
        {
            try
            {
                OrderItem oi = new OrderItem();

                JObject ja = (JObject)JsonConvert.DeserializeObject(str);
                string json = ja.Last.ToString();
                setDoubleToSingle(ref json);

                var resultObjects = AllChildren(JObject.Parse(json)).
                        First(c => c.Type == JTokenType.Array && c.Path.Contains("data")).
                        Children<JObject>();

                foreach (JObject result in resultObjects)
                {
                    oi = JsonConvert.DeserializeObject<OrderItem>(result.ToString());
                    observation.Add(oi);
                }
            }
            catch (Exception e)
            {
                Log.LogHelper.Error("getData() " + e.Message);
            }
        }

4  other

#region    Traverse 
        private static IEnumerable<JToken> AllChildren(JToken json)
        {
            foreach (var c in json.Children())
            {
                yield return c;
                foreach (var cc in AllChildren(c))
                {
                    yield return cc;
                }
            }
        }
#endregion

#region  Change double quotation marks into single quotation marks 
        public static void setDoubleToSingle(ref string str)
        {
            str = str.Replace("\r\n", "");
            str = str.Replace("\"", "'");
            str = str.Insert(0, "{");
            str = str.Insert(str.Length, "}");
        }
#endregion