Visual Basic

xml = %userdocs%\MyProgramm\XML\xmlfile.xml
xsd = %userdocs%\MyProgramm\Schema\schemafile.xsd

Dim reader As XmlReader = XmlReader.Create("contosoBooks.xml", settings)

<?xml version="1.0"?>
<MyTool xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Settings>
    <AdReqs/>
  </Settings>
</MyTool>

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="urn:MyTool">
  <xs:element name="Settings">
    <xs:complexType>
      <xs:sequence>
        <xs:element name ="AddReqs" default="Y">
          <xs:simpleType>
            <xs:restriction base="xs:string">
              <xs:enumeration value="Y"/>
              <xs:enumeration value="N"/>
            </xs:restriction>
          </xs:simpleType>
        </xs:element >
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

Imports System.Xml.Schema
Imports System.Xml.XPath
Imports System.Text

Public Class TXmlValidator
    Implements IXmlValidator

    Private vErrLst As List(Of String) = New List(Of String)

    Sub ValidateXml(ByVal xmlFile As String, ByVal xsdFile As String) Implements IXmlValidator.ValidateXml

        Try
            Dim settings As Xml.XmlReaderSettings = New Xml.XmlReaderSettings()
            settings.Schemas.Add("urn:MyTool", xsdFile)
            settings.ValidationType = Xml.ValidationType.Schema

            Dim reader As Xml.XmlReader = Xml.XmlReader.Create(xmlFile, settings)

            Dim document As Xml.XmlDocument = New Xml.XmlDocument()
            document.Load(reader)

            Dim eventHandler As ValidationEventHandler = New ValidationEventHandler(AddressOf ValidationEventHandler)

            ' the following call to Validate succeeds.
            document.Validate(eventHandler)

            reader.Close()
            reader = Nothing
            document = Nothing

        Catch ex As Exception
            MsgBox(ex.Message)

        End Try
    End Sub

    Sub ValidateXml1(ByVal xmlFile As String, ByVal xsdFile As String) Implements IXmlValidator.ValidateXml1
        Try
            Dim xsdMarkup As XElement = XElement.Load(xsdFile)
            Dim schemas As XmlSchemaSet = New XmlSchemaSet()
            schemas.Add("urn:MyTool", xsdMarkup.CreateReader)
            Dim document As XDocument = XDocument.Load(xmlFile)

            ' the following call to Validate succeeds.
            document.Validate(schemas, AddressOf ValidationEventHandler)
            document = Nothing
        Catch ex As Exception
            MsgBox(ex.Message)
        
        End Try
    End Sub


    Public ReadOnly Property GetErrorList() As List(Of String) Implements IXmlValidator.GetErrorList

        Get
            Return vErrLst
        End Get

    End Property

    Private Sub ValidationEventHandler(ByVal sender As Object, ByVal e As ValidationEventArgs)

        Select Case e.Severity
            Case XmlSeverityType.Error
                vErrLst.Add(String.Format("Error in line: {0} = {1}", e.Exception.LineNumber, e.Message))
            Case XmlSeverityType.Warning
                vErrLst.Add(String.Format("Warning in line: {0} = {1}", e.Exception.LineNumber, e.Message))
        End Select
        'fw.Close()
        'End Using

    End Sub

End Class

Dim xv As IXmlValidator = New TXmlValidator()
xv.ValidateXml(Me.TxtXml.Text, Me.TxtXsd.Text)
Dim qry As List(Of String) = xv.GetErrorList()
Dim iErr As Integer = qry.Count()

Me.LstOfErrors.Items.Add(String.Format("Errors count: {0} - document is {1} valid!", iErr.ToString(), IIf(iErr > 0, "not", "")))

xv.ValidateXml1(Me.TxtXml.Text, Me.TxtXsd.Text)
qry = xv.GetErrorList()
iErr = qry.Count()
Me.LstOfErrors.Items.Add(String.Format("Errors count: {0} - document is {1} valid!", iErr.ToString(), IIf(iErr > 0, "not", "")))

xv = Nothing