CODEWITHSUNDEEP
c#xmlcharacter-encodingxsdxmlreader
user3122648
user3122648

Reputation: 917

There is no Unicode byte order mark. Cannot switch to Unicode

I am writing an XML validator with XSD.

Below is what I did, but when the validator reached the line while (list.Read()) it gives me the error

There is no Unicode byte order mark. Cannot switch to Unicode.

Can anybody help me fix it?

public class Validator
    {
        public void Validate(string xmlString)
        {
            Boolean bRet = true;
            string xmlPath = @"C:\x.xml";
            string xsdPath = @"C:\general.xsd";

            XmlReaderSettings Settings = new XmlReaderSettings();
            Settings.Schemas.Add("", xsdPath);
            Settings.ValidationType = ValidationType.Schema;
            Settings.ValidationEventHandler += 
               new ValidationEventHandler(SettingsValidationEventHandler);

            XmlReader list = XmlReader.Create(xmlPath, Settings);
            //StringBuilder output = new StringBuilder();
            while (list.Read()) 
            {
            }
            //File.WriteAllText(@"D:\Output.xml", output.ToString());
        }
        static void SettingsValidationEventHandler(object sender,
                                                   ValidationEventArgs e)
        {
            if (e.Severity == XmlSeverityType.Warning)
            {
                MessageBox.Show( "WARNING: ");
                MessageBox.Show(e.Message);
            }
            else if (e.Severity == XmlSeverityType.Error)
            {
                MessageBox.Show("ERROR: ");
                MessageBox.Show(e.Message);
            }
        }
    }

XML

<?xml version="1.0" encoding="utf-16"?>
<FlashList xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:xsd="http://www.w3.org/2001/XMLSchema" vin="xxxxxxxxxxxxx">
  <flash ECUtype="xxx" />
</FlashList>

XSD

<?xml version="1.0" encoding="utf-16"?>
<xs:schema attributeFormDefault="unqualified" 
           elementFormDefault="qualified"
           xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="FlashList">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="flash" maxOccurs="unbounded" minOccurs="0">
          <xs:complexType>
            <xs:simpleContent>
              <xs:extension base="xs:string">
                <xs:attribute type="xs:string" name="ECUtype" use="optional"/>
              </xs:extension>
            </xs:simpleContent>
          </xs:complexType>
        </xs:element>
        <xs:element name="Error" maxOccurs="unbounded" minOccurs="0">
          <xs:complexType>
            <xs:simpleContent>
              <xs:extension base="xs:string">
                <xs:attribute type="xs:byte" name="code" use="optional" />
              </xs:extension>
            </xs:simpleContent>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
      <xs:attribute type="xs:string" name="vin"/>
    </xs:complexType>
  </xs:element>
</xs:schema>

Upvotes: 57

Views: 80106

Answers (4)

BJury
BJury

Reputation: 2604

You can use a StreamReader to set the encoding:

  return (TReport)xmlSerializer.Deserialize(
      new StreamReader(
          new FileStream(filename, FileMode.Open, FileAccess.Read), Encoding.UTF8));

Depending on your application, it might not be optimal to use a string to pass the xml, consider a stream instead.

Upvotes: 0

Jakub G
Jakub G

Reputation: 199

This error is thrown, when you declare encoding by UTF-16 in XML head, but physically don't save this file in such encoding.

You can check using simple Windows Notepad, clicking to Save As, and then in the bottom check encoding of xml file (probably it is still UTF-8, instead of UTF-16).

Screenshot of notepad encoding setting

Upvotes: 4

Emre Kabaoglu
Emre Kabaoglu

Reputation: 13146

If you are not able to change the xml file encoding as

<?xml version="1.0"?>

Alternatively, you can read the xml content directly as raw xml instead of loading it with xml path.

XmlReader.Create(new StringReader(File.ReadAllText(fileName)));

If you use XmlDocument;

var xmlDoc = new XmlDocument();
xmlDoc.LoadXml(File.ReadAllText(filePath));

Upvotes: 3

kjhughes
kjhughes

Reputation: 111621

The reality of your file's encoding appears to conflict with that specified by your XML declaration. If your file actually uses one-byte characters, declaring encoding="utf-16" won't change it to use two-byte characters, for example.

Try removing the conflicting encoding from the XML declaration. Replace

<?xml version="1.0" encoding="utf-16"?>

with

<?xml version="1.0"?>

You may also be able to load the file into a string as a work-around using LoadXML().

Upvotes: 100

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