I have an XML file with a specified schema location such as this:
xsi:schemaLocation="someurl ..\localSchemaPath.xsd"
I want to validate in C#. Visual Studio, when I open the file, validates it against the schema and lists errors perfectly. Somehow, though, I can't seem to validate it automatically in C# without specifying the schema to validate against like so:
XmlDocument asset = new XmlDocument();
XmlTextReader schemaReader = new XmlTextReader("relativeSchemaPath");
XmlSchema schema = XmlSchema.Read(schemaReader, SchemaValidationHandler);
asset.Schemas.Add(schema);
asset.Load(filename);
asset.Validate(DocumentValidationHandler);
Shouldn't I be able to validate with the schema specified in the XML file automatically ? What am I missing ?
The following example validates an XML file and generates the appropriate error or warning.
using System;
using System.IO;
using System.Xml;
using System.Xml.Schema;
public class Sample
{
public static void Main()
{
//Load the XmlSchemaSet.
XmlSchemaSet schemaSet = new XmlSchemaSet();
schemaSet.Add("urn:bookstore-schema", "books.xsd");
//Validate the file using the schema stored in the schema set.
//Any elements belonging to the namespace "urn:cd-schema" generate
//a warning because there is no schema matching that namespace.
Validate("store.xml", schemaSet);
Console.ReadLine();
}
private static void Validate(String filename, XmlSchemaSet schemaSet)
{
Console.WriteLine();
Console.WriteLine("\r\nValidating XML file {0}...", filename.ToString());
XmlSchema compiledSchema = null;
foreach (XmlSchema schema in schemaSet.Schemas())
{
compiledSchema = schema;
}
XmlReaderSettings settings = new XmlReaderSettings();
settings.Schemas.Add(compiledSchema);
settings.ValidationEventHandler += new ValidationEventHandler(ValidationCallBack);
settings.ValidationType = ValidationType.Schema;
//Create the schema validating reader.
XmlReader vreader = XmlReader.Create(filename, settings);
while (vreader.Read()) { }
//Close the reader.
vreader.Close();
}
//Display any warnings or errors.
private static void ValidationCallBack(object sender, ValidationEventArgs args)
{
if (args.Severity == XmlSeverityType.Warning)
Console.WriteLine("\tWarning: Matching schema not found. No validation occurred." + args.Message);
else
Console.WriteLine("\tValidation error: " + args.Message);
}
}
The preceding example uses the following input files.
<?xml version='1.0'?>
<bookstore xmlns="urn:bookstore-schema" xmlns:cd="urn:cd-schema">
<book genre="novel">
<title>The Confidence Man</title>
<price>11.99</price>
</book>
<cd:cd>
<title>Americana</title>
<cd:artist>Offspring</cd:artist>
<price>16.95</price>
</cd:cd>
</bookstore>
books.xsd
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="urn:bookstore-schema"
elementFormDefault="qualified"
targetNamespace="urn:bookstore-schema">
<xsd:element name="bookstore" type="bookstoreType"/>
<xsd:complexType name="bookstoreType">
<xsd:sequence maxOccurs="unbounded">
<xsd:element name="book" type="bookType"/>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="bookType">
<xsd:sequence>
<xsd:element name="title" type="xsd:string"/>
<xsd:element name="author" type="authorName"/>
<xsd:element name="price" type="xsd:decimal"/>
</xsd:sequence>
<xsd:attribute name="genre" type="xsd:string"/>
</xsd:complexType>
<xsd:complexType name="authorName">
<xsd:sequence>
<xsd:element name="first-name" type="xsd:string"/>
<xsd:element name="last-name" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:schema>
personally I favor validating without a callback:
public bool ValidateSchema(string xmlPath, string xsdPath)
{
XmlDocument xml = new XmlDocument();
xml.Load(xmlPath);
xml.Schemas.Add(null, xsdPath);
try
{
xml.Validate(null);
}
catch (XmlSchemaValidationException)
{
return false;
}
return true;
}
(see Timiz0r's post in Synchronous XML Schema Validation? .NET 3.5)
I had do this kind of automatic validation in VB and this is how I did it (converted to C#):
XmlReaderSettings settings = new XmlReaderSettings();
settings.ValidationType = ValidationType.Schema;
settings.ValidationFlags = settings.ValidationFlags |
Schema.XmlSchemaValidationFlags.ProcessSchemaLocation;
XmlReader XMLvalidator = XmlReader.Create(reader, settings);
Then I subscribed to the settings.ValidationEventHandler
event while reading the file.
A simpler way, if you are using .NET 3.5, is to use XDocument
and XmlSchemaSet
validation.
XmlSchemaSet schemas = new XmlSchemaSet();
schemas.Add(schemaNamespace, schemaFileName);
XDocument doc = XDocument.Load(filename);
string msg = "";
doc.Validate(schemas, (o, e) => {
msg += e.Message + Environment.NewLine;
});
Console.WriteLine(msg == "" ? "Document is valid" : "Document invalid: " + msg);
See the MSDN documentation for more assistance.
Source: Stackoverflow.com