I am trying to serialize an object to XML and the problem that I am getting is that the object gets serialized to
<something />
instead of
<something/>
I believe that both are valid XML syntax, but I have to get <something/>
Here is my code
public static string Serialize<T>(T ObjectToSerialize)
{
XmlWriterSettings settings = new XmlWriterSettings()
{
OmitXmlDeclaration = true,
Encoding = Encoding.UTF8,
};
XmlSerializer xmlSerializer = new XmlSerializer(ObjectToSerialize.GetType());
using (StringWriter textWriter = new StringWriter())
{
using (var xw = XmlWriter.Create(textWriter, settings))
{
xmlSerializer.Serialize(xw, ObjectToSerialize);
}
return textWriter.ToString();
}
}
How can I fix it?
May not be the most efficient solution, but you could do a simple String.Replace before returning serialized data in Serialize<T>().
Replacing
return textWriter.ToString();
With
return textWriter.ToString().Replace(" />","/>");
Related
Recently upgraded a 3.5 project to 4.5. There is a chunk of data that we are serializing and storing in the database, but everytime a save occurs in the upgraded project, the XML formatting has changed, throwing errors, and I can't seem to figure out the core issue. There are 2 SO questions in particular that mention encoding changes, but I've tried switching to UTF8 (in a few different ways specified in the answers on those questions), without any success - with UTF8 I just got a mess of strange characters throughout the entire file.
The main issues that I can see occurring are:
A leading ? character is added to the XML (which I've come to find out is a valid character, but we aren't handling apparently)
Child nodes aren't being included with some of the nodes.
Here is our serialization method:
public static string SerializeXml<T>(T instance)
{
XmlSerializer serializer = new XmlSerializer(typeof(T));
MemoryStream memStream = new MemoryStream();
XmlTextWriter xmlWriter = new XmlTextWriter(memStream, Encoding.Unicode);
serializer.Serialize(xmlWriter, instance);
memStream = (MemoryStream)xmlWriter.BaseStream;
return UnicodeEncoding.Unicode.GetString(memStream.ToArray()).Replace("<?xml version=\"1.0\" encoding=\"utf-16\"?>", "");
}
and our deserialization method:
public static T DeserializeXml<T>(string xml)
{
XmlSerializer xs = new XmlSerializer(typeof(T));
StringReader reader = new StringReader(xml);
return (T)xs.Deserialize(reader);
}
Any help would be appreciated, I am not too familiar with serialization or encoding. Just curious what may have changed with the upgrade to 4.5, or if there is something I need to take a closer look at.
If you want to Serialize to a String you need to use UTF16. If you want to Serialize with UTF8 you need to serialize to a byte[]. Strings in C# are UTF16 so in the code you posted I believe all your data is encoded with UTF16 but because you are omitting the Xml Declaration code assumes it is UTF8.
I would recommend using functions like this and not omitting the XmlDeclaration:
public static string SerializeXmlToString<T>(T instance)
{
XmlSerializer serializer = new XmlSerializer(typeof(T));
XmlWriterSettings settings = new XmlWriterSettings();
settings.Encoding = Encoding.Unicode;
StringBuilder builder = new StringBuilder();
using (StringWriter writer = new StringWriter(builder))
using (XmlWriter xmlWriter = XmlWriter.Create(writer, settings))
{
serializer.Serialize(xmlWriter, instance);
}
return builder.ToString();
}
public static byte[] SerializeXml<T>(T instance)
{
XmlSerializer serializer = new XmlSerializer(typeof(T));
XmlWriterSettings settings = new XmlWriterSettings();
settings.Encoding = Encoding.UTF8;
using (MemoryStream memStream = new MemoryStream())
{
using (XmlWriter xmlWriter = XmlWriter.Create(memStream, settings))
{
serializer.Serialize(xmlWriter, instance);
}
return memStream.ToArray();
}
}
public static T DeserializeXml<T>(string data)
{
XmlSerializer serializer = new XmlSerializer(typeof(T));
using (StringReader reader = new StringReader(data))
{
return (T)serializer.Deserialize(reader);
}
}
public static T DeserializeXml<T>(byte[] bytes)
{
XmlSerializer serializer = new XmlSerializer(typeof(T));
using(MemoryStream stream = new MemoryStream(bytes))
{
return (T)serializer.Deserialize(stream);
}
}
I seem to be getting some junk at the head of my serialized XML string. I have a simple extension method
public static string ToXML(this object This)
{
DataContractSerializer ser = new DataContractSerializer(This.GetType());
var settings = new XmlWriterSettings { Indent = true };
using (MemoryStream ms = new MemoryStream())
using (var w = XmlWriter.Create(ms, settings))
{
ser.WriteObject(w, This);
w.Flush();
return UTF8Encoding.Default.GetString(ms.ToArray());
}
}
and when I apply it to my object I get the string
<?xml version="1.0" encoding="utf-8"?>
<RootModelType xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/WeinCad.Data">
<MoineauPump xmlns:d2p1="http://schemas.datacontract.org/2004/07/Weingartner.Numerics">
<d2p1:Rotor>
<d2p1:Equidistance>0.0025</d2p1:Equidistance>
<d2p1:Lobes>2</d2p1:Lobes>
<d2p1:MajorRadius>0.04</d2p1:MajorRadius>
<d2p1:MinorRadius>0.03</d2p1:MinorRadius>
</d2p1:Rotor>
</MoineauPump>
</RootModelType>
Note the junk at the beginning. When I try to deserialize this
I get an error. If I copy paste the XML into my source minus
the junk prefix I can deserialize it. What is the junk text
and how can I remove it or handle it?
Note my deserialization code is
public static RootModelType Load(Stream data)
{
DataContractSerializer ser = new DataContractSerializer(typeof(RootModelType));
return (RootModelType)ser.ReadObject(data);
}
public static RootModelType Load(string data)
{
using(var stream = new MemoryStream(Encoding.UTF8.GetBytes(data))){
return Load(stream);
}
}
This fix seems to work
public static string ToXML(this object obj)
{
var settings = new XmlWriterSettings { Indent = true };
using (MemoryStream memoryStream = new MemoryStream())
using (StreamReader reader = new StreamReader(memoryStream))
using(XmlWriter writer = XmlWriter.Create(memoryStream, settings))
{
DataContractSerializer serializer =
new DataContractSerializer(obj.GetType());
serializer.WriteObject(writer, obj);
writer.Flush();
memoryStream.Position = 0;
return reader.ReadToEnd();
}
}
I need to set the OmitXmlDeclaration property of the XmlWriterSettings for a XmlWriter to false to not have XML declarations created. The issue is that I have created the XmlWriter from a call of a XPathNavigator.AppendChild() method. Code below:
public String GetEntityXml<T>(List<T> entities)
{
XmlDocument xmlDoc = new XmlDocument();
XPathNavigator nav = xmlDoc.CreateNavigator();
using (XmlWriter writer = nav.AppendChild())
{
XmlSerializer ser = new XmlSerializer(typeof(List<T>), new XmlRootAttribute(typeof(T).Name + "_LIST"));
ser.Serialize(writer, entities);
}
StringWriter stringWriter = new StringWriter();
XmlTextWriter xmlTextWriter = new XmlTextWriter(stringWriter);
xmlDoc.WriteTo(xmlTextWriter);
string resultString = stringWriter.ToString();
stringWriter.Close();
xmlTextWriter.Close();
return resultString;
}
Any idea how to serialize the List and not have XML declarations?
I’m not getting the XML declaration when I execute your code. Serializing a List<int> gives me:
<Int32_LIST xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<int>5</int>
<int>7</int>
<int>2</int>
</Int32_LIST>
Note that the “XML declaration” that OmitXmlDeclaration refers to is typically something similar to:
<?xml version="1.0" encoding="UTF-8" ?>
If you’re instead referring to the xmlns parts, then those are called “XML namespace declarations”, and may be eliminated by initializing an XmlSerializerNamespaces instance with a default empty namespace, and passing it to your Serialize method:
XmlSerializer ser = new XmlSerializer(typeof(List<T>), new XmlRootAttribute(typeof(T).Name + "_LIST"));
var namespaces = new XmlSerializerNamespaces(new[] { new XmlQualifiedName("", "") });
ser.Serialize(writer, entities, namespaces);
The below is a shortened implementation which achieves the same result as your code:
public String GetEntityXml<T>(List<T> entities)
{
var sb = new StringBuilder();
var settings = new XmlWriterSettings { OmitXmlDeclaration = true };
using (XmlWriter writer = XmlWriter.Create(sb, settings))
{
XmlSerializer ser = new XmlSerializer(typeof(List<T>), new XmlRootAttribute(typeof(T).Name + "_LIST"));
var namespaces = new XmlSerializerNamespaces(new[] { new XmlQualifiedName("", "") });
ser.Serialize(writer, entities, namespaces);
}
return sb.ToString();
}
Try this approach (switched to var for readability):
public String GetEntityXml<T>(List<T> entities)
{
var xmlDoc = new XmlDocument();
var nav = xmlDoc.CreateNavigator();
using (var sw = new StringWriter())
{
//Create an XmlWriter that will omit xml declarations
var s = new XmlWriterSettings{ OmitXmlDeclaration = true };
using (var xmlWriter = XmlWriter.Create(sw, s))
{
//Use the following to serialize without namespaces
var ns = new XmlSerializerNamespaces();
ns.Add("", "");
var ser = new XmlSerializer(typeof(List<T>),
new XmlRootAttribute(typeof(T).Name + "_LIST"));
ser.Serialize(xmlWriter, entities, ns);
}
//Pass xml string to nav.AppendChild()
nav.AppendChild(sw.ToString());
}
using (var stringWriter = new StringWriter())
{
using (var xmlTextWriter = XmlWriter.Create(stringWriter))
{
xmlDoc.WriteTo(xmlTextWriter);
}
return stringWriter.ToString();
}
}
Rather than using nav.AppendChild() to create the XmlWriter, you can create the XmlWriter separately and then just use nav.AppendChild(string) to write the XML into xmlDoc. When you create the XmlWriter yourself, you can omit the XML declaration. Also, when you serialize, you'll probably want to omit the xmlns:xsi and xmlns:xsd namespaces using the XmlSerializerNamespaces class.
I am sending a request to a web service which requires a string containing XML, of which I have been giving an XSD.
I've ran xsd.exe and created a class based on this but am unsure of the best way to create the xml string to send, for example a stream, XMLDocument or some form of serialization.
UPDATE
I found this here
public static string XmlSerialize(object o)
{
using (var stringWriter = new StringWriter())
{
var settings = new XmlWriterSettings
{
Encoding = Encoding.GetEncoding(1252),
OmitXmlDeclaration = true
};
using (var writer = XmlWriter.Create(stringWriter, settings))
{
var xmlSerializer = new XmlSerializer(o.GetType());
xmlSerializer.Serialize(writer, o);
}
return stringWriter.ToString();
}
}
which lets me control the tag attribute.
What I am doing on several occasions is creating a class/struct to hold the data on the client-side program and serializing the data as a string. Then I make the web request and send it that XML string. Here is the code I use to serialize an object to XML:
public static string SerializeToString(object o)
{
string serialized = "";
System.Text.StringBuilder sb = new System.Text.StringBuilder();
//Serialize to memory stream
System.Xml.Serialization.XmlSerializer ser = new System.Xml.Serialization.XmlSerializer(o.GetType());
System.IO.TextWriter w = new System.IO.StringWriter(sb);
ser.Serialize(w, o);
w.Close();
//Read to string
serialized = sb.ToString();
return serialized;
}
As long as all the contents of the object are serializable it will serialize any object.
Use Xstream framework to generate an xml string. Hope this helps!
Here's what I have done before:
private static string CreateXMLString(object o)
{
XmlSerializer serializer = new XmlSerializer(typeof(object));
var stringBuilder = new StringBuilder();
using (var writer = XmlWriter.Create(stringBuilder))
{
serializer.Serialize(writer, o);
}
return stringBuilder.ToString();
}
I need to get plain xml, without the <?xml version="1.0" encoding="utf-16"?> at the beginning and xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" in first element from XmlSerializer. How can I do it?
To put this all together - this works perfectly for me:
// To Clean XML
public string SerializeToString<T>(T value)
{
var emptyNamespaces = new XmlSerializerNamespaces(new[] { XmlQualifiedName.Empty });
var serializer = new XmlSerializer(value.GetType());
var settings = new XmlWriterSettings();
settings.Indent = true;
settings.OmitXmlDeclaration = true;
using (var stream = new StringWriter())
using (var writer = XmlWriter.Create(stream, settings))
{
serializer.Serialize(writer, value, emptyNamespaces);
return stream.ToString();
}
}
Use the XmlSerializer.Serialize method overload where you can specify custom namespaces and pass there this.
var emptyNs = new XmlSerializerNamespaces(new[] { XmlQualifiedName.Empty });
serializer.Serialize(xmlWriter, objectToSerialze, emptyNs);
passing null or empty array won't do the trick
You can use XmlWriterSettings and set the property OmitXmlDeclaration to true as described in the msdn. Then use the XmlSerializer.Serialize(xmlWriter, objectToSerialize) as described here.
This will write the XML to a file instead of a string. Object ticket is the object that I am serializing.
Namespaces used:
using System.Xml;
using System.Xml.Serialization;
Code:
XmlSerializerNamespaces emptyNamespaces = new XmlSerializerNamespaces(new[] { XmlQualifiedName.Empty });
XmlSerializer serializer = new XmlSerializer(typeof(ticket));
XmlWriterSettings settings = new XmlWriterSettings
{
Indent = true,
OmitXmlDeclaration = true
};
using (XmlWriter xmlWriter = XmlWriter.Create(fullPathFileName, settings))
{
serializer.Serialize(xmlWriter, ticket, emptyNamespaces);
}