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XML Deserialization C#

I am trying to deserialize an XML file into an object in the Program file of my Windows Forms application as below:
List<UserAccessGroup> AccessGroups = new List<UserAccessGroup>();
AccessGroups = SerializerHelper.DeSerializeObject<List<UserAccessGroup>>(#"C:\Users\Michael"
+ #"\Google Drive\FDM Dev Course Content\Workspace\SystemAdmin\SystemAdmin\"
+ #"XML Data Store\UserAccessGroups.xml");
UserAccessGroup SystemAdmin_App = new UserAccessGroup();
foreach (UserAccessGroup group in AccessGroups)
{
if (group.Name.Equals("Admin Operators"))
{
SystemAdmin_App = group;
}
}
When I run this code, I am getting an unhandled exception in my foreach loop, stating that Access Groups is null.
However, when I copy and paste this snippet of code into a blank console application, it runs fine and when I check AccessGroups with a break point, it has 4 members, as expected.
Can anyone please tell me why deserialization is not working in my program file?
Also, here is my XML file:
<?xml version="1.0"?>
<ArrayOfUserAccessGroup xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<UserAccessGroup>
<Name>Admin Operators</Name>
<Access_Group>
<int>999</int>
</Access_Group>
</UserAccessGroup>
<UserAccessGroup>
<Name>Shareholders</Name>
<Access_Group />
</UserAccessGroup>
<UserAccessGroup>
<Name>Brokers</Name>
<Access_Group />
</UserAccessGroup>
<UserAccessGroup>
<Name>StockExMgrs</Name>
<Access_Group />
</UserAccessGroup>
</ArrayOfUserAccessGroup>
EDIT: forgot to include the SerializerHelper class that I am using for serialization/deserialization, please see below:
public static class SerializerHelper
{
/// <summary>
/// Serializes an object.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="serializableObject"></param>
/// <param name="fileName"></param>
private static readonly log4net.ILog logger = log4net.LogManager.GetLogger(
"SerializerHelper.cs");
public static void SerializeObject<T>(string filepath, T serializableObject)
{
if (serializableObject == null) { return; }
try
{
XmlDocument xmlDocument = new XmlDocument();
XmlSerializer serializer = new XmlSerializer(serializableObject.GetType());
using (MemoryStream stream = new MemoryStream())
{
serializer.Serialize(stream, serializableObject);
stream.Position = 0;
xmlDocument.Load(stream);
xmlDocument.Save(filepath);
stream.Close();
}
}
catch (Exception ex)
{
//Log exception here
logger.Error("Error Serializing: " + ex.Message);
}
}
/// <summary>
/// Deserializes an xml file into an object list
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="fileName"></param>
/// <returns></returns>
public static T DeSerializeObject<T>(string filepath)
{
T objectOut = default(T);
if (!System.IO.File.Exists(filepath)) return objectOut;
try
{
string attributeXml = string.Empty;
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.Load(filepath);
string xmlString = xmlDocument.OuterXml;
using (StringReader read = new StringReader(xmlString))
{
Type outType = typeof(T);
XmlSerializer serializer = new XmlSerializer(outType);
using (XmlReader reader = new XmlTextReader(read))
{
objectOut = (T)serializer.Deserialize(reader);
reader.Close();
}
read.Close();
}
}
catch (Exception ex)
{
//Log exception here
logger.Error("Error Deserializing: " + ex.Message);
}
return objectOut;
}
}
EDIT: UserAccessGroup class below:
[Serializable]
public class UserAccessGroup : IUserAccessGroup
{
private String name;
private List<int> AccessGroup = new List<int>();
public String Name
{
get { return name; }
set { name = value; }
}
public List<int> Access_Group
{
get { return AccessGroup; }
set { AccessGroup = value; }
}
public UserAccessGroup()
{
}
public UserAccessGroup(String name)
{
this.name = name;
}
public List<int> getUserIDs()
{
return AccessGroup;
}
public void removeUser(int userID)
{
AccessGroup.Remove(userID);
return;
}
public void addUser(int userID)
{
AccessGroup.Add(userID);
return;
}
}

The main problem can be summarized as:
T objectOut = default(T);
if (!System.IO.File.Exists(filepath)) return objectOut;
try
{
// ...
}
catch (Exception ex)
{
//Log exception here
logger.Error("Error Deserializing: " + ex.Message);
}
return objectOut;
(note that default(T) for T=List<UserAccessGroup> is null)
So: for AccessGroups to be null, one of 2 things is happening:
the file does not exist (so the code is exiting near the top)
an exception is being thrown
Check each of these. If the first: add it. If the second: read the .Message, and the .InnerException.Message etc (XmlSerializer is very big on inner-exceptions)
XmlSerializer will not return null for the root object of a list / array, so: it is one of those two things.
Put a breakpoint on the not-exists return, and in the catch, and you should find what is happening. Alternatively, look at where-ever logger writes. Maybe also add something that writes to logger when the file doesn't exist.

C# Modifying multiple Dictionary Values throws error

I'm using HTML Agility Pack to download some pages, I'm also storing cookie info and login info from a form. The issue I'm having is that I'm doing a GET operation to get the cookie info and form details so on the next step it can login using a username and password, I'm then trying to set the value of the username and password input fields so that I can then post to a login page. The input fields are being stored in a Dictionary<string,string>. I'm able to change one of the dictionary values, but after that I get the error:
"Object reference not set to an instance of an object.".
If I try to change password and then username the username throws the error and vice-versa. This is the code im using:
class Main
{
private void testLogin()
{
BrowserSession b = new BrowserSession();
b.Get("login.html");
b.FormElements["email_address"] = #"email";
b.FormElements["password"] = "password";
string response = b.Post("index.php?main_page=login");
}
}
}
public class BrowserSession
{
private bool _isPost;
private HtmlDocument _htmlDoc;
/// <summary>
/// System.Net.CookieCollection. Provides a collection container for instances of Cookie class
/// </summary>
public CookieCollection Cookies { get; set; }
/// <summary>
/// Provide a key-value-pair collection of form elements
/// </summary>
public FormElementCollection FormElements { get; set; }
/// <summary>
/// Makes a HTTP GET request to the given URL
/// </summary>
public string Get(string url)
{
_isPost = false;
CreateWebRequestObject().Load(url);
return _htmlDoc.DocumentNode.InnerHtml;
}
/// <summary>
/// Makes a HTTP POST request to the given URL
/// </summary>
public string Post(string url)
{
_isPost = true;
CreateWebRequestObject().Load(url, "POST");
return _htmlDoc.DocumentNode.InnerHtml;
}
/// <summary>
/// Creates the HtmlWeb object and initializes all event handlers.
/// </summary>
private HtmlWeb CreateWebRequestObject()
{
HtmlWeb web = new HtmlWeb();
web.UseCookies = true;
web.PreRequest = new HtmlWeb.PreRequestHandler(OnPreRequest);
web.PostResponse = new HtmlWeb.PostResponseHandler(OnAfterResponse);
web.PreHandleDocument = new HtmlWeb.PreHandleDocumentHandler(OnPreHandleDocument);
return web;
}
/// <summary>
/// Event handler for HtmlWeb.PreRequestHandler. Occurs before an HTTP request is executed.
/// </summary>
protected bool OnPreRequest(HttpWebRequest request)
{
AddCookiesTo(request); // Add cookies that were saved from previous requests
if (_isPost) AddPostDataTo(request); // We only need to add post data on a POST request
return true;
}
/// <summary>
/// Event handler for HtmlWeb.PostResponseHandler. Occurs after a HTTP response is received
/// </summary>
protected void OnAfterResponse(HttpWebRequest request, HttpWebResponse response)
{
SaveCookiesFrom(response); // Save cookies for subsequent requests
}
/// <summary>
/// Event handler for HtmlWeb.PreHandleDocumentHandler. Occurs before a HTML document is handled
/// </summary>
protected void OnPreHandleDocument(HtmlDocument document)
{
SaveHtmlDocument(document);
}
/// <summary>
/// Assembles the Post data and attaches to the request object
/// </summary>
private void AddPostDataTo(HttpWebRequest request)
{
string payload = FormElements.AssemblePostPayload();
byte[] buff = Encoding.UTF8.GetBytes(payload.ToCharArray());
request.ContentLength = buff.Length;
request.ContentType = "application/x-www-form-urlencoded";
System.IO.Stream reqStream = request.GetRequestStream();
reqStream.Write(buff, 0, buff.Length);
}
/// <summary>
/// Add cookies to the request object
/// </summary>
private void AddCookiesTo(HttpWebRequest request)
{
if (Cookies != null && Cookies.Count > 0)
{
request.CookieContainer.Add(Cookies);
}
}
/// <summary>
/// Saves cookies from the response object to the local CookieCollection object
/// </summary>
private void SaveCookiesFrom(HttpWebResponse response)
{
if (response.Cookies.Count > 0)
{
if (Cookies == null) Cookies = new CookieCollection();
Cookies.Add(response.Cookies);
}
}
/// <summary>
/// Saves the form elements collection by parsing the HTML document
/// </summary>
private void SaveHtmlDocument(HtmlDocument document)
{
_htmlDoc = document;
FormElements = new FormElementCollection(_htmlDoc);
}
}
public class FormElementCollection : Dictionary<string, string>
{
/// <summary>
/// Constructor. Parses the HtmlDocument to get all form input elements.
/// </summary>
public FormElementCollection(HtmlDocument htmlDoc)
{
var inputs = htmlDoc.DocumentNode.SelectSingleNode("//div[#id = 'loginDefault']").Descendants("input");
foreach (var element in inputs)
{
string name = element.GetAttributeValue("name", "undefined");
string value = element.GetAttributeValue("value", "");
if (!name.Equals("undefined")) { Add(name, value); }
}
}
/// <summary>
/// Assembles all form elements and values to POST. Also html encodes the values.
/// </summary>
public string AssemblePostPayload()
{
StringBuilder sb = new StringBuilder();
foreach (var element in this)
{
string value = HttpUtility.UrlEncode(element.Value);
sb.Append("&" + element.Key + "=" + value);
}
return sb.ToString().Substring(1);
}
}
Any help would be much appreciated.

While debugging put a break point after calling the b constractor.
You ll find the FormElements property is Null.
You need to inialize it in BrowserSession constractor.

Calling a method in C#

I have problem to call a method in a WCFService. I downladed the file below for a project and I want to call a method in SampleHttpResquestAndResponse class in my WCFService (Also, I tried to do it in a main method and i couldn't succeed it either). However I can't do it, i can't find the method when I type it. How to call those methods in SampleHttpResquestAndResponse class?
using System;
using System.IO;
using System.Net;
using System.Text;
using System.IO.Compression;
using System.Xml.Serialization;
namespace Sample
{
public class SampleHttpResquestAndResponse
{
/// <summary>
/// Adonis servisi ile iletişim kurmayı sağlar.
/// </summary>
/// <typeparam name="T">T</typeparam>
/// <param name="prm_ServiceName">string</param> SearchHotels // BasketHotels // ConfirmHotels
/// <param name="prm_Criteria">object</param>
/// <param name="prm_Url">string</param> "http://xmltest.adonis.com/AdonisServices"
/// <returns>T</returns>
public static T AdonisRequestResponseMethod<T>(string prm_ServiceName, object prm_Criteria, string prm_Url)
{
#region Variables
HttpWebRequest HttpWebRequest;
T ReturnValue;
#endregion
try
{
#region Xml Serializer
var XmlString = SampleHttpResquestAndResponse.ConvertTypeToXml<object>(prm_Criteria).ToString();
#endregion
#region Http Web Request
HttpWebRequest = (HttpWebRequest)WebRequest.Create(string.Format("{0}/{1}?prm_CurrentData={2}", prm_Url, prm_ServiceName, XmlString));
HttpWebRequest.ContentType = "text/xml;charset=\"utf-8\"";
HttpWebRequest.Method = "POST";
HttpWebRequest.Timeout = 80000000;
#endregion
#region Http Web Response
StreamWriter StreamWriterPost = new StreamWriter(HttpWebRequest.GetRequestStream());
StreamWriterPost.Write(XmlString);
StreamWriterPost.Close();
HttpWebResponse HttpWebResponse = (HttpWebResponse)HttpWebRequest.GetResponse();
StreamReader StreamReaderResponse = new StreamReader(HttpWebResponse.GetResponseStream(), Encoding.UTF8);
string StringResponse = string.Empty;
if (HttpWebResponse.ContentEncoding.ToLower().Contains("gzip"))
{
using (GZipStream decompress = new GZipStream(HttpWebResponse.GetResponseStream(), CompressionMode.Decompress))
{
StreamReader reader = new StreamReader(decompress);
StringResponse = reader.ReadToEnd();
}
}
else
{
StreamReader reader = new StreamReader(HttpWebResponse.GetResponseStream(), Encoding.UTF8);
StringResponse = reader.ReadToEnd();
}
#endregion
#region Return Value Type Process (DESERIALIZE)
ReturnValue = SampleHttpResquestAndResponse.ConvertXmlToType<T>(StringResponse.ToString()).Data;
#endregion
#region Return Value
return ReturnValue;
#endregion
}
catch (Exception ex)
{
#region Return Value
return ReturnValue = SampleHttpResquestAndResponse.ConvertXmlToType<T>(ex.Message).Data;
#endregion
}
}
public static ResultDTO<T> ConvertXmlToType<T>(string prm_Xml)
{
#region Variables
T ReturnValue;
#endregion
try
{
#region Replace String Value
prm_Xml = prm_Xml.Replace("xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\""
, "xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"");
prm_Xml = prm_Xml.Replace("<", "<").Replace(">", ">").Replace(""", "\"");
#endregion
#region Deserialize
using (MemoryStream MemoryStream = new MemoryStream())
{
using (StreamWriter StreamWriter = new StreamWriter(MemoryStream))
{
StreamWriter.Write(prm_Xml);
StreamWriter.Flush();
MemoryStream.Position = 0;
XmlSerializer XmlSerializer = new XmlSerializer(typeof(T));
using (StreamReader StreamReader = new StreamReader(MemoryStream))
{
StreamReader.ReadLine();
#region Result Value (SET)
ReturnValue = (T)XmlSerializer.Deserialize(StreamReader);
#endregion
}
}
}
#endregion
#region Return Value
return new ResultDTO<T>
{
Data = ReturnValue,
Success = true
};
#endregion
}
catch (Exception ex)
{
#region Return Value
return new ResultDTO<T>
{
Success = false,
Message = string.Format("Error Type : {0} Code : {1} Method Name : {2} Error Mesage : {3}", "Undetermined", "1000", "ConvertXmlToType", ex.Message),
};
#endregion
}
}
public static string ConvertTypeToXml<T>(T prm_Criteria)
{
#region Variables
XmlSerializer XmlSerializer;
StringWriter StringWriter = new StringWriter();
#endregion
try
{
#region Xml Serializer
XmlSerializer = new XmlSerializer(prm_Criteria.GetType());
XmlSerializer.Serialize(StringWriter, prm_Criteria);
var XmlString = StringWriter.ToString();
#endregion
#region Request Replace
return XmlString = XmlString.Replace("<?xml version=\"1.0\" encoding=\"utf-16\"?>", "");
#endregion
}
catch (Exception ex)
{
throw ex;
}
finally
{
GC.SuppressFinalize(StringWriter);
}
}
}
public class ResultDTO
{
#region Properties
/// <summary>
/// İslem durumu.
/// </summary>
public bool Success { get; set; }
/// <summary>
/// İşlem mesajı.
/// </summary>
public string Message { get; set; }
#endregion
}
public class ResultDTO<T> : ResultDTO
{
#region Fields
/// <summary>
/// Generic data tipi.
/// </summary>
private T data = Activator.CreateInstance<T>();
#endregion
#region Properties
/// <summary>
/// Generic data tipi
/// </summary>
public T Data
{
get
{
if (data == null)
return data = default(T);
return data;
}
set { data = value; }
}
#endregion
}
}
PS: I know it is a little bit silly question, but i couldn't figure it. If it is needed, the below is how i try to call any method in this class in a simple way
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.IO;
using System.Net;
using System.Text;
using System.IO.Compression;
using System.Xml.Serialization;
using Sample;
namespace Adonis
{
// NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "AdonisService" in code, svc and config file together.
// NOTE: In order to launch WCF Test Client for testing this service, please select AdonisService.svc or AdonisService.svc.cs at the Solution Explorer and start debugging.
public class AdonisService : IAdonisService
{
ResultDTO res = new ResultDTO();
SampleHttpResquestAndResponse samp = new SampleHttpResquestAndResponse();
public string results()
{
string a1 = "";
object c = new object();
c = 434;
string b = "";
string a = "";
a= samp.AdonisRequestResponseMethod(a, c, b);
}
}
}

AdonisRequestResponseMethod is static, and as such would be called like this:
SampleHttpResquestAndResponse.AdonisRequestResponseMethod(a, b, c);
However, it is also a generic method, so you will have to supply the type you require:
SampleHttpResquestAndResponse.AdonisRequestResponseMethod<string>(a, b, c);

I see 2 things wrong here:
The method is both a generic method.
Since it's a generic method, you must provide a type for it:
SampleHttpResquestAndResponse samp = new SampleHttpResquestAndResponse ();
samp.AdonisRequestResponseMethod<SomeType>(a, b, c);
However, that's not the complete answer,
It's a static method, which means that you can't reference the method from an instance of the class, rather you must reference it from the class type
SampleHttpResquestAndResponse.AdonisRequestResponseMethod<SomeType>(a, b, c);
Oh, and one more thing... SampleHttpResquestAndResponse has an extra 's' in the 'Request' portion of the name. That might give you headaches later. Hope this helps!

Json Geocode address parsing in C#

I want to get address of the location
Iam using google geocode to get address by passing lat and long.
static readonly string RequestUrl = "http://maps.google.com/maps/api/geocode/json?";
/// <summary>
/// Gets the raw object.
/// </summary>
/// <returns></returns>
protected JsonGeoData GetJsonObject() {
StringBuilder url = new StringBuilder( GeoRequest.RequestUrl);
if (this.Location != null) {
url.AppendFormat("latlng={0}", this.Location.ToString());
}
else {
url.AppendFormat("address={0}", HttpUtility.UrlEncode(this.Address));
}
url.AppendFormat("&sensor={0}", this.IsSensor.ToString().ToLower());
if (!string.IsNullOrEmpty(this.Language))
url.AppendFormat("&language={0}", HttpUtility.UrlEncode(this.Language));
if(!string.IsNullOrEmpty(this.Region))
url.AppendFormat("&region={0}", HttpUtility.UrlEncode(this.Region));
WebRequest request = WebRequest.Create(url.ToString());
using (WebResponse response = request.GetResponse()) {
using (StreamReader reader = new StreamReader(response.GetResponseStream())) {
JavaScriptSerializer serializer = new JavaScriptSerializer();
return serializer.Deserialize<JsonGeoData>(reader.ReadToEnd());
}
}
}
/// <summary>
/// Gets the response.
/// </summary>
/// <returns></returns>
public GeoResponse GetResponse() {
return new GeoResponse(this.GetJsonObject());
}
/// <summary cref="A">
/// fetching location from web
/// </summary>
/// <typeparam name="T"></typeparam>
private string getloc(double plat, double plng)
{
try
{
GeoRequest objreq = new GeoRequest(plat, plng);
GeoResponse objres = objreq.GetResponse();
if (objres.Results.Count > 0)
{ return objres.Results[0].FormattedAddress; }
else
{ return "Unknown"; }
}
catch (FormatException) { return "Unknown"; }
catch (Exception)
{ return "Unknown"; }
}
iam trying to get json data from geocode and parse using serializer,
But iam getting error 'sublocality_level_2 is not a valid value for GeoAddressType.'

How to pass a data from new thread?

I have a class:
class ShowComboBoxUpdater
{
private ComboBox _showComboBox;
private String _searchString;
private RequestState _endState;
public event EventHandler ResultUpdated;
public string[] getShowList()
{
if (_endState.serverQueryResult != null)
return _endState.serverQueryResult;
return new string[] { "" };
}
public ShowComboBoxUpdater(ComboBox combo, Image refreshImage)
{
_showComboBox = combo;
_refreshImage = refreshImage;
_endState = new RequestState();
}
public void RequestUpdatingComboSource()
{
_searchString = _showComboBox.Text;
Thread t = new Thread(new ThreadStart(MakeServerConnectionThread));
t.IsBackground = true;
t.Start();
}
private void MakeServerConnectionThread()
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://services.tvrage.com/myfeeds/search.php?show=" + _searchString);
_endState.request = request;
IAsyncResult result = request.BeginGetResponse(new AsyncCallback(RequestingThread), _endState);
ThreadPool.RegisterWaitForSingleObject(result.AsyncWaitHandle, new WaitOrTimerCallback(ScanTimeoutCallback), _endState, (30 * 1000), true);
}
private void RequestingThread(IAsyncResult result)
{
RequestState state = (RequestState)result.AsyncState;
WebRequest request = (WebRequest)state.request;
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(result);
Stream bodyStream = response.GetResponseStream();
StreamReader r = new StreamReader(bodyStream);
string xmlResponse = r.ReadToEnd().Trim();
using (StringReader XMLStream = new StringReader(xmlResponse))
{
XPathNavigator feed = new XPathDocument(XMLStream).CreateNavigator();
XPathNodeIterator nodesNavigator = (XPathNodeIterator)feed.Evaluate("descendant::show/name/text()");
int titlesCount = nodesNavigator.Count;
string[] titles = new string[titlesCount];
foreach (XPathNavigator n in nodesNavigator)
{
titles[--titlesCount] = n.Value;
}
state.serverQueryResult = titles;
if (this.ResultUpdated != null) this.ResultUpdated(this, new EventArgs());
}
}
private static void ScanTimeoutCallback(object state, bool timedOut)
{
if (timedOut)
{
RequestState reqState = (RequestState)state;
if (reqState != null)
reqState.request.Abort();
}
}
}
In my main thread I create ShowComboBoxUpdater and connect event ResultUpdate to other event. Then I am calling RequestUpdatingComboSource() method. I have my event activated but, how can I get the resulting serverQueryResult ? I know it's there but everything that I try results in exception that what I want to get is "owned by other thread".

How to pass value ?
public class MyArgs : EventArgs
{
//Declare any specific type here
public string ResultToPass { get; private set; }
public MyArgs()
{
}
}
if (this.ResultUpdated != null) this.ResultUpdated(this, new MyArgs(){ResultToPass="Your actual result"} );
How to update result ?
Capture SynchronizationContext of the UI ( main thread) in order to instruct whenever you want the value to be updated back in the UI. Send/Post method on the captured SynchronizationContext reference in order to push the message into UI thread.
public partial class MainWindow : Window
{
SynchronizationContext UISyncContext;
public MainWindow()
{
InitializeComponent();
}
public StartProcessing()
{
//Let say this method is been called from UI thread. i.e on a button click
//capture the current synchronization context
UISyncContext=TaskScheduler.FromCurrentSynchronizationContext;
}
public UpdateResultInUI()
{
//Let's say this is is the method which user triggers at
//some point in time ( with the assumption that we have Myresult in hand)
if(UISyncContext!=null)
UISyncContext.Send(new SendOrPostCallback(delegate{ PutItInUI }),null);
//Use Send method - to send your request synchronously
//Use Post method- to send your request asynchronously
}
void PutItInUI()
{
//this method help you to put your result in UI/controls
}