No root element found. Issue? - c#

I've just wanted to use the XML-Serializer of the .NET framework(version 2.0).
I created to methods to serialize and deserialize my settings:
public static void Save(string filename)
{
var settings = Settings.Instance;
if (File.Exists(filename))
File.Delete(filename);
using (var stream = File.OpenWrite(filename))
{
XmlSerializer serializer = new XmlSerializer(typeof(Settings));
serializer.Serialize(stream, settings);
}
}
The Save-methods works really fine and as a result I get the following xml document:
<?xml version="1.0"?>
<Settings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<EnableHooking>true</EnableHooking>
<IncludePressedKeys>false</IncludePressedKeys>
<EnableFastScroll>false</EnableFastScroll>
<FastScrollingHotKeys>
<VirtualKeys>Control</VirtualKeys>
<VirtualKeys>Alt</VirtualKeys>
</FastScrollingHotKeys>
<ScrollSpeed>2</ScrollSpeed>
<FastScrollSpeed>10</FastScrollSpeed>
</Settings>
If I try to deserialize this document I get an exception XmlException which tells me that the root element is missing. I've tried to set the XmlRootAttribute, tried to check the filenames and stream position. Everything is ok. Now I finally tried to read load the file through the XmlDocument class which works perfectly. Now I really don't know what happens. So you may take a look at the Load-method:
public static void Load(string filename)
{
if (!File.Exists(filename))
throw new ArgumentException("File not found.", "filename", new FileNotFoundException());
//works
var doc = new XmlDocument();
doc.Load(XmlReader.Create(File.OpenRead(filename)));
Console.WriteLine(doc.DocumentElement.FirstChild);
using (var stream = File.OpenRead(filename))
{
XmlSerializer serializer = new XmlSerializer(typeof(Settings));
_instance = serializer.Deserialize(stream) as Settings;
}
}
Hopefully anyone got an idea.

When I use the following code (in which I added a simple version of the Settings class) on OSX with Xamarin Studio, I get no errors.
using System;
using System.IO;
using System.Xml;
using System.Xml.Serialization;
namespace Test
{
class MainClass
{
private static Settings _instance;
public static void Main (string[] args)
{
Load ("Settings.xml");
}
public static void Load(string filename)
{
if (!File.Exists(filename))
throw new ArgumentException("File not found.", "filename", new FileNotFoundException());
//works
var doc = new XmlDocument();
doc.Load(XmlReader.Create(File.OpenRead(filename)));
Console.WriteLine(doc.DocumentElement.FirstChild);
using (var stream = File.OpenRead(filename))
{
XmlSerializer serializer = new XmlSerializer(typeof(Settings));
_instance = serializer.Deserialize(stream) as Settings;
}
}
}
public class Settings
{
public bool EnableHooking {
get;
set;
}
public bool IncludePressedKeys {
get;
set;
}
}
}
When I check the value of _instance, the properties are set to the right values. I stripped the XML after the second property. The problem might be in more "complex" XmlElement "FastScrollingHotKeys". Could you post your Settings class, please?

Related

ignore xml-attribut when deserialising [duplicate]

Can I make XmlSerializer ignore the namespace (xmlns attribute) on deserialization so that it doesn't matter if the attribute is added or not or even if the attribute is bogus? I know that the source will always be trusted so I don't care about the xmlns attribute.
Yes, you can tell the XmlSerializer to ignore namespaces during de-serialization.
Define an XmlTextReader that ignores namespaces. Like so:
// helper class to ignore namespaces when de-serializing
public class NamespaceIgnorantXmlTextReader : XmlTextReader
{
public NamespaceIgnorantXmlTextReader(System.IO.TextReader reader): base(reader) { }
public override string NamespaceURI
{
get { return ""; }
}
}
// helper class to omit XML decl at start of document when serializing
public class XTWFND : XmlTextWriter {
public XTWFND (System.IO.TextWriter w) : base(w) { Formatting= System.Xml.Formatting.Indented;}
public override void WriteStartDocument () { }
}
Here's an example of how you would de-serialize using that TextReader:
public class MyType1
{
public string Label
{
set { _Label= value; }
get { return _Label; }
}
private int _Epoch;
public int Epoch
{
set { _Epoch= value; }
get { return _Epoch; }
}
}
String RawXml_WithNamespaces = #"
<MyType1 xmlns='urn:booboo-dee-doo'>
<Label>This document has namespaces on its elements</Label>
<Epoch xmlns='urn:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'>0</Epoch>
</MyType1>";
System.IO.StringReader sr;
sr= new System.IO.StringReader(RawXml_WithNamespaces);
var s1 = new XmlSerializer(typeof(MyType1));
var o1= (MyType1) s1.Deserialize(new NamespaceIgnorantXmlTextReader(sr));
System.Console.WriteLine("\n\nDe-serialized, then serialized again:\n");
XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
ns.Add("urn", "booboo-dee-doo");
s1.Serialize(new XTWFND(System.Console.Out), o1, ns);
Console.WriteLine("\n\n");
The result is like so:
<MyType1>
<Label>This document has namespaces on its elements</Label>
<Epoch>0</Epoch>
</MyType1>
If you expect no namespace, but the input has namespaces, then you can set
Namespaces = false
on your XmlTextReader.
Exdended Wolfgang Grinfeld answer (w/o exception handling):
public static Message Convert(XmlDocument doc)
{
Message obj;
using (TextReader textReader = new StringReader(doc.OuterXml))
{
using (XmlTextReader reader = new XmlTextReader(textReader))
{
reader.Namespaces = false;
XmlSerializer serializer = new XmlSerializer(typeof(Message));
obj = (Message)serializer.Deserialize(reader);
}
}
return obj;
}
Solved this by using XmlSerializer Deserialize to read from xml instead from stream. This way before xml is Deserialized, using Regex to remove xsi:type from the xml. Was doing this is Portable Class Library for Cross Platform, so did not had many other options :(. After this the deserialization seems to work fine.
Following code can help,
public static TClass Deserialize<TClass>(string xml) where TClass : class, new()
{
var tClass = new TClass();
xml = RemoveTypeTagFromXml(xml);
var xmlSerializer = new XmlSerializer(typeof(TClass));
using (TextReader textReader = new StringReader(xml))
{
tClass = (TClass)xmlSerializer.Deserialize(textReader);
}
return tClass;
}
public static string RemoveTypeTagFromXml(string xml)
{
if (!string.IsNullOrEmpty(xml) && xml.Contains("xsi:type"))
{
xml = Regex.Replace(xml, #"\s+xsi:type=""\w+""", "");
}
return xml;
}
Why try to make the XmlSerializer forget how XML works? It's a fact of XML that two elements with the same name but different namespaces are different elements.
If you want to process XML that has no namespaces, then you should pre-process it to remove the namespaces, and then pass it to the serializer.

Change XML opener(reader) to JSON

I have followed a good tutorial that shows how to make an Automation Framework in C# Selenium.
The config file is in XML at the moment, but I wanted some more practice and change it to a .json file.
At the moment we are using the namespace System.Xml.XPath; and my question is, are there a similar for JSON? Lets say "System.Json;" that works the same as my XML reader. So I don't need to refactor to much code, or is it unavoidably?
This is how it works at the moment.
//Initialize
ConfigReader.SetFrameworkSettings();
public class ConfigReader
{
public static void SetFrameworkSettings()
{
XPathItem aut;
string strFilename = Environment.CurrentDirectory.ToString() + "\\Config\\GlobalConfig.xml";
FileStream stream = new FileStream(strFilename, FileMode.Open);
XPathDocument document = new XPathDocument(stream);
XPathNavigator navigator = document.CreateNavigator();
//Get XML Details and pass it in XPathItem type variables
aut = navigator.SelectSingleNode("AutoFramework/RunSettings/AUT");
Settings.AUT = aut.Value.ToString();
}
}
public class Settings
{
public static string AUT { get; set; }
}
Would be awesome if you could just change this two lines
XPathDocument document = new XPathDocument(stream);
XPathNavigator navigator = document.CreateNavigator()
And the XpathItem
Cheers
I would recommend using Newtonsoft.Json which is available from Nuget.
To "reuse" your current code you would have to make some basic SettingsConverter first:
public static class SettingsConverter
{
public static string FromXmlToJson(string xml)
{
Settings settings = null;
// read your xml file and assign values to the settings object
// now you can "serialize" settings object into Json
return JsonSerialization.Serialize(settings);
}
public static string FromJsonToXml(string json)
{
Settings settings = JsonSerialization.Deserialize<MeSettings>(json);
// save settings using your "xml" serialization
return xmlString; // return xml string
}
}
To use these methods I'm using this JsonSerialization helper class :
public static class JsonSerialiation
{
public static string Serialize<T>(T obj)
{
using (MemoryStream stream = new MemoryStream())
{
using (JsonTextWriter writer = new JsonTextWriter(new StreamWriter(stream))
{
JsonSerializer serializer = new JsonSerializer();
serializer.Serializer(writer, obj);
writer.Flush();
stream.Position = 0;
using (StreamReader reader = new StreamREader(stream))
{
return reader.ReadToEnd();
}
}
}
}
public static T Deserialize<T>(string jsonString)
{
using (JsonTextReader reader = new JsonTextReader(new StringReader(str)))
{
JsonSerializer serializer = new JsonSerializer();
return serializer.Deserialize<T>(reader)
}
}
}
Above example requires from you to change your Settings class from static :
public class Settings
{
public static string AUT { get; set; }
}
To instance :
public class Settings
{
public string AUT { get; set; }
}
If you prefer to keep it as static. You should use JObject from Newtonsoft.Json library :
JObject obj = JObject.Parse(jsonString);
Settings.AUT = obj.SelectToken("AUT").Value<string>();
You can always use JsonConvert.Serialize<T>() and JsonConvert.Deserialize<T>() methods instead of the JsonSerialization helper class that I've made but in my opinion the less control you have over your code the bigger the problems will be.

Class serialization in XML

[XmlRoot("Class1")]
class Class1
{
[(XmlElement("Product")]
public string Product{get;set;}
[(XmlElement("Price")]
public string Price{get;set;}
}
This is my class. In this the price contains the '£' symbol. after serializing it to XML I get the '?' instead of '£'.
what I need to do to get the '£' in XML? OR How can I pass the data in price as CDATA?
Your problem must be to do with how the XML is written to the file.
I've written a program that uses the information that you've given me so far, and it when I print the XML string out, it is correct.
I conclude that the error is happening either when the data is written to the XML file, or when it is read back in from the XML file.
using System;
using System.Collections.Generic;
using System.IO;
using System.Xml;
using System.Xml.Serialization;
namespace ConsoleApplication1
{
class Program
{
static void Main()
{
new Program().Run();
}
void Run()
{
Class1 test = new Class1();
test.Product = "Product";
test.Price = "£100";
Test(test);
}
void Test<T>(T obj)
{
XmlSerializerNamespaces Xsn = new XmlSerializerNamespaces();
Xsn.Add("", "");
XmlSerializer submit = new XmlSerializer(typeof(T));
StringWriter stringWriter = new StringWriter();
XmlWriter writer = XmlWriter.Create(stringWriter);
submit.Serialize(writer, obj, Xsn);
var xml = stringWriter.ToString(); // Your xml This is the serialization code. In this Obj is the object to serialize
Console.WriteLine(xml); // £ sign is fine in this output.
}
}
[XmlRoot("Class1")]
public class Class1
{
[XmlElement("Product")]
public string Product
{
get;
set;
}
[XmlElement("Price")]
public string Price
{
get;
set;
}
}
}

Unknown attribute xsi:type in XmlSerializer

I am learning XML Serialization and meet an issue, I have two claess
[System.Xml.Serialization.XmlInclude(typeof(SubClass))]
public class BaseClass
{
}
public class SubClass : BaseClass
{
}
I am trying to serialize a SubClass object into XML file, I use blow code
XmlSerializer xs = new XmlSerializer(typeof(Base));
xs.Serialize(fs, SubClassObject);
I noticed Serialization succeed, but the XML file is kind of like
<?xml version="1.0"?>
<BaseClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:type="SubClass">
...
</Employee>
If I use
XmlSerializer xs = new XmlSerializer(typeof(Base));
SubClassObject = xs.Deserialize(fs) as SubClass;
I noticed it will complain xsi:type is unknown attribute(I registered an event), although all information embedded in the XML was parsed successfully and members in SubClassObject was restored correctly.
Anyone has any idea why there is error in parsing xsi:type and anything I did wrong?
Thanks
Here is the program that I wrote
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Serialization;
using System.IO;
namespace XmlIncludeExample
{
[XmlInclude(typeof(DerivedClass))]
public class BaseClass
{
public string ClassName = "Base Class";
}
public class DerivedClass : BaseClass
{
public string InheritedName = "Derived Class";
}
class Program
{
static void Main(string[] args)
{
string fileName = "Test.xml";
string fileFullPath = Path.Combine(Path.GetTempPath(), fileName);
try
{
DerivedClass dc = new DerivedClass();
using (FileStream fs = new FileStream(fileFullPath, FileMode.CreateNew))
{
XmlSerializer xs = new XmlSerializer(typeof(BaseClass));
xs.Serialize(fs, dc);
}
using (FileStream fs = new FileStream(fileFullPath, FileMode.Open))
{
XmlSerializer xs = new XmlSerializer(typeof(BaseClass));
DerivedClass dc2 = xs.Deserialize(fs) as DerivedClass;
}
}
finally
{
if (File.Exists(fileFullPath))
{
File.Delete(fileFullPath);
}
}
}
}
}
This produced the following xml
<?xml version="1.0" ?>
- <BaseClass xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:type="DerivedClass">
<ClassName>Base Class</ClassName>
<InheritedName>Derived Class</InheritedName>
</BaseClass>
And it worked
I got the same error.
I have not a great answer but this is what I have done:
using System;
using System.IO;
using System.Reflection;
using System.Xml;
using System.Xml.Serialization;
namespace HQ.Util.General
{
/// <summary>
/// Save by default as User Data Preferences
/// </summary>
public class XmlPersistence
{
// ******************************************************************
public static void Save<T>(T obj, string path = null) where T : class
{
if (path == null)
{
path = GetDefaultPath(typeof(T));
}
var serializer = new XmlSerializer(typeof(T));
using (TextWriter writer = new StreamWriter(path))
{
serializer.Serialize(writer, obj);
writer.Close();
}
}
// ******************************************************************
public static T Load<T>(string path = null,
Action<object, XmlNodeEventArgs> actionUnknownNode = null,
Action<object, XmlAttributeEventArgs> actionUnknownAttribute = null) where T : class
{
T obj = null;
if (path == null)
{
path = GetDefaultPath(typeof(T));
}
if (File.Exists(path))
{
var serializer = new XmlSerializer(typeof(T));
if (actionUnknownAttribute == null)
{
actionUnknownAttribute = UnknownAttribute;
}
if (actionUnknownNode == null)
{
actionUnknownNode = UnknownNode;
}
serializer.UnknownAttribute += new XmlAttributeEventHandler(actionUnknownAttribute);
serializer.UnknownNode += new XmlNodeEventHandler(actionUnknownNode);
using (var fs = new FileStream(path, FileMode.Open))
{
// Declares an object variable of the type to be deserialized.
// Uses the Deserialize method to restore the object's state
// with data from the XML document. */
obj = (T)serializer.Deserialize(fs);
}
}
return obj;
}
// ******************************************************************
private static string GetDefaultPath(Type typeOfObjectToSerialize)
{
return Path.Combine(AppInfo.AppDataFolder, typeOfObjectToSerialize.Name + ".xml");
}
// ******************************************************************
private static void UnknownAttribute(object sender, XmlAttributeEventArgs xmlAttributeEventArgs)
{
// Correction according to: https://stackoverflow.com/questions/42342875/xmlserializer-warns-about-unknown-nodes-attributes-when-deserializing-derived-ty/42407193#42407193
if (xmlAttributeEventArgs.Attr.Name == "xsi:type")
{
}
else
{
throw new XmlException("UnknownAttribute" + xmlAttributeEventArgs.ToString());
}
}
// ******************************************************************
private static void UnknownNode(object sender, XmlNodeEventArgs xmlNodeEventArgs)
{
// Correction according to: https://stackoverflow.com/questions/42342875/xmlserializer-warns-about-unknown-nodes-attributes-when-deserializing-derived-ty/42407193#42407193
if (xmlNodeEventArgs.Name == "xsi:type")
{
}
else
{
throw new XmlException("UnknownNode" + xmlNodeEventArgs.ToString());
}
}
// ******************************************************************
}
}

Serialization and Deserialization into an XML file, C#

I have the following code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
namespace ConsoleApplication28
{
class Program
{
static void Main()
{
List<string> dirs = FileHelper.GetFilesRecursive(#"c:\Documents and Settings\bob.smith\Desktop\Test");
foreach (string p in dirs)
{
Console.WriteLine(p);
}
//Write Count
Console.WriteLine("Count: {0}", dirs.Count);
Console.Read();
}
static class FileHelper
{
public static List<string> GetFilesRecursive(string b)
{
// 1.
// Store results in the file results list.
List<string> result = new List<string>();
// 2.
// Store a stack of our directories.
Stack<string> stack = new Stack<string>();
// 3.
// Add initial directory.
stack.Push(b);
// 4.
// Continue while there are directories to process
while (stack.Count > 0)
{
// A.
// Get top directory
string dir = stack.Pop();
try
{
// B
// Add all files at this directory to the result List.
result.AddRange(Directory.GetFiles(dir, "*.*"));
// C
// Add all directories at this directory.
foreach (string dn in Directory.GetDirectories(dir))
{
stack.Push(dn);
}
}
catch
{
// D
// Could not open the directory
}
}
return result;
}
}
}
}
The code above works well for recursively finding what files/directories lie in a folder on my c:.
I am trying to serialize the results of what this code does to an XML file but I am not sure how to do this.
My project is this: find all files/ directories w/in a drive, serialize into an XML file. Then, the second time i run this app, i will have two XML files to compare. I then want to deserialize the XML file from the first time i ran this app and compare differences to the current XML file and produce a report of changes (i.e. files that have been added, deleted, updated).
I was hoping to get some help as I am a beginner in C# and i am very very shaky on serializing and deserializing. I'm having lots of trouble coding. Can someone help me?
Thanks
Your result is List<string> and that is not directly serializable. You'll have to wrap it, a minimal approach:
[Serializable]
class Filelist: List<string> { }
And then the (De)Serialization goes like:
Filelist data = new Filelist(); // replaces List<string>
// fill it
using (var stream = File.Create(#".\data.xml"))
{
var formatter = new System.Runtime.Serialization.Formatters.Soap.SoapFormatter();
formatter.Serialize(stream, data);
}
data = null; // lose it
using (var stream = File.OpenRead(#".\data.xml"))
{
var formatter = new System.Runtime.Serialization.Formatters.Soap.SoapFormatter();
data = (Filelist) formatter.Deserialize(stream);
}
But note that you will not be comparing the XML in any way (not practical). You will compare (deserialzed) List instances. And the XML is SOAP formatted, take a look at it. It may not be very useful in another context.
And therefore you could easily use a different Formatter (binary is a bit more efficient and flexible).
Or maybe you just want to persist the List of files as XML. That is a different question.
For anyone who is having trouble with xml serialization and de-serialization. I have created a sample class to do this below. It works for recursive collections also (like files and directories).
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Sample
{
[Serializable()]
[System.Xml.Serialization.XmlRootAttribute(Namespace = "", IsNullable = false, ElementName = "rootnode")]
public partial class RootNode
{
[System.Xml.Serialization.XmlElementAttribute("collection1")]
public List<OuterCollection> OuterCollections { get; set; }
}
[Serializable()]
public partial class OuterCollection
{
[XmlAttribute("attribute1")]
public string attribute1 { get; set; }
[XmlArray(ElementName = "innercollection1")]
[XmlArrayItem("text", Type = typeof(InnerCollection1))]
public List<InnerCollection1> innerCollection1Stuff { get; set; }
[XmlArray("innercollection2")]
[XmlArrayItem("text", typeof(InnerCollection2))]
public List<InnerCollection2> innerConnection2Stuff { get; set; }
}
[Serializable()]
public partial class InnerCollection2
{
[XmlText()]
public string text { get; set; }
}
public partial class InnerCollection1
{
[XmlText()]
public int number { get; set; }
}
}
This class serializes and deserializes itself....hopefully this helps.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Xml.Serialization;
using System.Xml;
namespace TestStuff
{
public class Configuration
{
#region properties
public List<string> UIComponents { get; set; }
public List<string> Settings { get; set; }
#endregion
//serialize itself
public string Serialize()
{
MemoryStream memoryStream = new MemoryStream();
XmlSerializer xs = new XmlSerializer(typeof(Configuration));
using (StreamWriter xmlTextWriter = new StreamWriter(memoryStream))
{
xs.Serialize(xmlTextWriter, this);
xmlTextWriter.Flush();
//xmlTextWriter.Close();
memoryStream = (MemoryStream)xmlTextWriter.BaseStream;
memoryStream.Seek(0, SeekOrigin.Begin);
StreamReader reader = new StreamReader(memoryStream);
return reader.ReadToEnd();
}
}
//deserialize into itself
public void Deserialize(string xmlString)
{
String XmlizedString = null;
using (MemoryStream memoryStream = new MemoryStream())
{
using (StreamWriter w = new StreamWriter(memoryStream))
{
w.Write(xmlString);
w.Flush();
XmlSerializer xs = new XmlSerializer(typeof(Configuration));
memoryStream.Seek(0, SeekOrigin.Begin);
XmlReader reader = XmlReader.Create(memoryStream);
Configuration currentConfig = (Configuration)xs.Deserialize(reader);
this.Settings = currentConfig.Settings;
this.UIComponents = currentConfig.UIComponents;
w.Close();
}
}
}
static void Main(string[] args)
{
Configuration thisConfig = new Configuration();
thisConfig.Settings = new List<string>(){
"config1", "config2"
};
thisConfig.UIComponents = new List<string>(){
"comp1", "comp2"
};
//serializing the object
string serializedString = thisConfig.Serialize();
Configuration myConfig = new Configuration();
//deserialize into myConfig object
myConfig.Deserialize(serializedString);
}
}
}
John:
May I suggest an improvement? Instead of using filenames, use the FileInfo object. This will allow you to get much more accurate information about each file rather than just if it exists under the same name.
Also, the XmlSerializer class should do you just fine. It won't serialize generic lists, so you'll have to output your List<> to an array or some such, but other than that:
XmlSerializer serial = new XmlSerializer(typeof(FileInfo[]));
StringWriter writer = new StringWriter();
FileInfo[] fileInfoArray = GetFileInfos();
serial.Serialize(writer, fileInfoArrays);
Simple and easy, unless it matters to you how the serialized XML looks.
Whatever you do, lose the empty catch block. You WILL regret swallowing exceptions. Log them or re-throw them.
Help #1. Indent code by four spaces to have it be seen as code when you post here.
2: get rid of that try/catch block, as it will eat all exceptions, including the ones you want to know about.
3: Did you make any attempt at all to serialize your results? Please edit your question to show what you tried. Hint: use the XmlSerializer class.
for xml serialisation, you have several possibilities:
Doing it manually
Using XmlSerializer as detailed above
Using System.Xml.Serialization
Using Linq to Xml
for the last two, see a code example in this answer. (See some gotchas here)
And for your recursive directory visitor, you could consider making it really recursive: here's some interesting code examples.
This question is exactly like this one. I also have a posted answer which will work for you as well:
How to serialize?

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