validating-xml-with-xsd.cs

using System; 
using System.IO; 
using System.Xml; 
using System.Xml.Schema; 
using System.Xml.XPath; 

namespace XSD_fun 
{ 
    class Program 
    { 
        private static string xml = 
@"<?xml version=""1.0"" encoding=""utf-8"" ?> 
<bookstore xmlns = ""http://www.contoso.com/books""> 
    <book genre=""autobiography"" publicationdate=""1981-03-22"" ISBN=""1-861003-11-0""> 
        <title>The Autobiography of Benjamin Franklin</title> 
        <author> 
            <first-name>Benjamin</first-name> 
            <last-name>Franklin</last-name> 
        </author> 
        <price>8.99</price> 
    </book> 
    <book genre = ""novel"" publicationdate=""1967-11-17"" ISBN=""0-201-63361-2""> 
        <title>The Confidence Man</title> 
        <author> 
            <first-name>Herman</first-name> 
            <last-name>Melville</last-name> 
        </author> 
        <price>11.99</price> 
    </book> 
    <book genre = ""philosophy"" publicationdate=""1991-02-15"" ISBN=""1-861001-57-6""> 
        <title>The Gorgias</title> 
        <author> 
            <name>Plato</name> 
        </author> 
        <price>9.99</price> 
    </book> 
</bookstore>"; 

        private static string xsd = 
@"<?xml version=""1.0"" encoding=""utf-8""?> 
<xs:schema attributeFormDefault = ""unqualified"" elementFormDefault=""qualified"" targetNamespace=""http://www.contoso.com/books"" xmlns:xs=""http://www.w3.org/2001/XMLSchema""> 
    <xs:element name = ""bookstore""> 
        <xs:complexType> 
            <xs:sequence> 
                <xs:element maxOccurs = ""unbounded"" name=""book""> 
                    <xs:complexType> 
                        <xs:sequence> 
                            <xs:element name = ""title"" type=""xs:string"" /> 
                            <xs:element name = ""author""> 
                                <xs:complexType> 
                                    <xs:sequence> 
                                        <xs:element minOccurs = ""0"" name=""name"" type=""xs:string"" /> 
                                        <xs:element minOccurs = ""0"" name=""first-name"" type=""xs:string"" /> 
                                        <xs:element minOccurs = ""0"" name=""last-name"" type=""xs:string"" /> 
                                    </xs:sequence> 
                                </xs:complexType> 
                            </xs:element> 
                            <xs:element name = ""price"" type=""xs:decimal"" /> 
                        </xs:sequence> 
                        <xs:attribute name = ""genre"" type=""xs:string"" use=""required"" /> 
                        <xs:attribute name = ""publicationdate"" type=""xs:date"" use=""required"" /> 
                        <xs:attribute name = ""ISBN"" type=""xs:string"" use=""required"" /> 
                    </xs:complexType> 
                </xs:element> 
            </xs:sequence> 
        </xs:complexType> 
    </xs:element> 
</xs:schema>"; 

        private static string xmlFilename = "books.xml"; 
        private static string xsdFilename = "books.xsd"; 

        static void Main() 
        { 
            try 
            { 
                File.WriteAllText(xmlFilename, xml); 
                File.WriteAllText(xsdFilename, xsd); 

                XmlReaderSettings settings = new XmlReaderSettings(); 
                settings.Schemas.Add("http://www.contoso.com/books", xsdFilename); 
                settings.ValidationType = ValidationType.Schema; 

                XmlReader reader = XmlReader.Create(xmlFilename, settings); 
                XmlDocument document = new XmlDocument(); 
                document.Load(reader); 

                ValidationEventHandler eventHandler = new ValidationEventHandler(ValidationEventHandler); 

                // the following call to Validate succeeds. 
                document.Validate(eventHandler); 

                // add a node so that the document is no longer valid 
                XPathNavigator navigator = document.CreateNavigator(); 
                navigator.MoveToFollowing("price", "http://www.contoso.com/books"); 
                XmlWriter writer = navigator.InsertAfter(); 
                writer.WriteStartElement("anotherNode", "http://www.contoso.com/books"); 
                writer.WriteEndElement(); 
                writer.Close(); 

                // the document will now fail to successfully validate 
                document.Validate(eventHandler); 
            } 
            catch (Exception ex) 
            { 
                Console.WriteLine(ex.Message); 
            } 
        } 
        
        static void ValidationEventHandler(object sender, ValidationEventArgs e) 
        { 
            switch (e.Severity) 
            { 
                case XmlSeverityType.Error: 
                    Console.WriteLine("Error: {0}", e.Message); 
                    break; 
                case XmlSeverityType.Warning: 
                    Console.WriteLine("Warning {0}", e.Message); 
                    break; 
            } 

        } 
    } 
}