Here is an example class that writes validation warning, validation
errors and well-formedness exceptions to the console:

Imports System
Imports System.Xml
Imports System.Xml.Schema
Imports System.IO

Module TestValidation
    Sub Main()
        Dim xml As String = "<root><foo>1</foo></root>"
        Dim schema As String = "..\..\XSDSchema1.xsd"
        Dim validator As New ValidateXml(xml, schema)
        Dim valid As Boolean = validator.Validate()
        Console.WriteLine("{0} is valid: {1}.", xml, valid)

    End Sub
End Module

Public Class ValidateXml

    Private _valid As Boolean
    Public Property Valid() As Boolean
        Get
            Return _valid
        End Get
        Set(ByVal value As Boolean)
            _valid = value
        End Set
    End Property

    Private _xml As String
    Public Property Xml() As String
        Get
            Return _xml
        End Get
        Set(ByVal value As String)
            _xml = value
        End Set
    End Property

    Private _schemaFile As String
    Public Property SchemaFile() As String
        Get
            Return _schemaFile
        End Get
        Set(ByVal value As String)
            _schemaFile = value
        End Set
    End Property

    Public Sub New(ByVal x As String, ByVal schema As String)
        _xml = x
        _schemaFile = schema
    End Sub

    Public Function Validate() As Boolean
        _valid = True
        Dim settings As New XmlReaderSettings()
        settings.ValidationType = ValidationType.Schema
        settings.ValidationFlags = settings.ValidationFlags Or
XmlSchemaValidationFlags.ReportValidationWarnings
        AddHandler settings.ValidationEventHandler, AddressOf
ValidationHandler
        settings.Schemas.Add(Nothing, _schemaFile)
        Using reader As XmlReader = XmlReader.Create(New
StringReader(_xml), settings)
            Try
                While reader.Read()
                End While
            Catch ex As XmlException
                Console.WriteLine("Parse error: {0}", ex.Message)
                _valid = False
            End Try
            Return _valid
        End Using
    End Function

    Private Sub ValidationHandler(ByVal sender As Object, ByVal vargs
As ValidationEventArgs)
        If vargs.Severity = XmlSeverityType.Error Then
            _valid = False
        End If
        Console.WriteLine("{0}: {1}", vargs.Severity, vargs.Message)
    End Sub
End Class