VB.NET - Erro no acesso a arquivo XSD

[r.fagioli]

Olá pessoal

Criei uma aplicação para bricar um pouco com a criação e validação de arquivos XML. Então, criei uma função que valida um arquivo XML baseado em um arquivo XSD. O código dessa função é esse:

       Private Shared Function ValidateXML() As Boolean
            Dim ValidatingReader As XmlReader

            Dim ReaderSettings As New XmlReaderSettings

            Try
                CreateXMLSchema()

                ValidatingXmlStatus = True

                AddHandler ReaderSettings.ValidationEventHandler, AddressOf ReaderSettings_ValidationEventHandler

                ReaderSettings.ValidationType = ValidationType.Schema

                ReaderSettings.Schemas.Add(Nothing, Application.StartupPath + "\" + strXMLSchemaName)

                ValidatingReader = XmlReader.Create(Application.StartupPath + "\" + strXMLName, ReaderSettings)

                While ValidatingReader.Read()
                End While

                Return ValidatingXmlStatus
            Catch ex As Exception
                MessageBox.Show("Ocorreu uma exceção: " + vbCrLf + vbCrLf + ex.Message, strAppName, MessageBoxButtons.OK, MessageBoxIcon.Error)

                Return False
            Finally
                If File.Exists(Application.StartupPath + "\" + strXMLSchemaName) Then File.Delete(Application.StartupPath + "\" + strXMLSchemaName)

                ReaderSettings = Nothing

                ValidatingReader = Nothing

                GC.Collect()
            End Try

A função chama o método CreateXmlSchema que é esse a seguir:

       Private Shared Sub CreateXMLSchema()
            Dim NameSpaceManager As New XmlNamespaceManager(New NameTable())

            Dim SchemaSet As New XmlSchemaSet

            Dim NewSchema As New XmlSchema

            Dim CompiledSchema As New XmlSchema

            Dim mElement As New XmlSchemaElement()

            Dim mElementComplexType As New XmlSchemaComplexType

            Dim mElementSequence As New XmlSchemaSequence

            Dim sElement(2) As XmlSchemaElement

            Dim sElementComplexType(2) As XmlSchemaComplexType

            Dim sElementSequence(2) As XmlSchemaSequence

            Dim element As New XmlSchemaElement

            Dim elementSimpleType As New XmlSchemaSimpleType

            Dim elementSimpleTypeRestriction As New XmlSchemaSimpleTypeRestriction

            Dim elementMinLenghtFacet As New XmlSchemaMinLengthFacet

            Dim elementMaxLenghtFacet As New XmlSchemaMaxLengthFacet

            Try
                If File.Exists(Application.StartupPath + "\" + strXMLSchemaName) Then File.Delete(Application.StartupPath + "\" + strXMLSchemaName)

                elementMinLenghtFacet.Value = 1

                elementMaxLenghtFacet.Value = 60

                elementSimpleTypeRestriction.BaseTypeName = New XmlQualifiedName("string", "http://www.w3.org/2001/XMLSchema")
                elementSimpleTypeRestriction.Facets.Add(elementMinLenghtFacet)
                elementSimpleTypeRestriction.Facets.Add(elementMaxLenghtFacet)

                elementSimpleType.Content = elementSimpleTypeRestriction

                element.Name = strXmlNodeChildElementName1
                element.MinOccurs = 1
                element.MaxOccurs = 1
                element.SchemaType = elementSimpleType

                sElementSequence(0) = New XmlSchemaSequence
                sElementSequence(0).Items.Add(element)

                sElementComplexType(0) = New XmlSchemaComplexType
                sElementComplexType(0).Particle = sElementSequence(0)

                sElement(0) = New XmlSchemaElement
                sElement(0).Name = strXmlNodeChildName1
                sElement(0).MinOccurs = 0
                sElement(0).MaxOccurs = 1
                sElement(0).SchemaType = sElementComplexType(0)

                sElementSequence(1) = New XmlSchemaSequence
                sElementSequence(1).Items.Add(element)

                sElementComplexType(1) = New XmlSchemaComplexType
                sElementComplexType(1).Particle = sElementSequence(1)

                sElement(1) = New XmlSchemaElement
                sElement(1).Name = strXmlNodeChildName2
                sElement(1).MinOccurs = 0
                sElement(1).MaxOccurs = 1
                sElement(1).SchemaType = sElementComplexType(1)

                sElementSequence(2) = New XmlSchemaSequence
                sElementSequence(2).Items.Add(element)

                sElementComplexType(2) = New XmlSchemaComplexType
                sElementComplexType(2).Particle = sElementSequence(2)

                sElement(2) = New XmlSchemaElement
                sElement(2).Name = strXmlNodeChildName3
                sElement(2).MinOccurs = 0
                sElement(2).MaxOccurs = 1
                sElement(2).SchemaType = sElementComplexType(2)

                mElementSequence.Items.Add(sElement(0))
                mElementSequence.Items.Add(sElement(1))
                mElementSequence.Items.Add(sElement(2))

                mElementComplexType.Particle = mElementSequence

                mElement.Name = strXmlNodeName
                mElement.SchemaType = mElementComplexType

                NewSchema.AttributeFormDefault = XmlSchemaForm.Qualified
                NewSchema.ElementFormDefault = XmlSchemaForm.Qualified
                NewSchema.Items.Add(mElement)

                NameSpaceManager.AddNamespace("xs", "http://www.w3.org/2001/XMLSchema")

                AddHandler SchemaSet.ValidationEventHandler, AddressOf SchemaSet_ValidationCallbackOne

                SchemaSet.Add(NewSchema)
                SchemaSet.Compile()

                For Each TempSchema As XmlSchema In SchemaSet.Schemas()
                    CompiledSchema = TempSchema
                Next

                CompiledSchema.Write(File.Create(Application.StartupPath + "\" + strXMLSchemaName), NameSpaceManager)
            Catch ex As Exception
                MessageBox.Show("Ocorreu uma exceção: " + vbCrLf + vbCrLf + ex.Message, strAppName, MessageBoxButtons.OK, MessageBoxIcon.Error)
            Finally
                elementMinLenghtFacet = Nothing

                elementMaxLenghtFacet = Nothing

                elementSimpleTypeRestriction = Nothing

                elementSimpleType = Nothing

                element = Nothing

                sElementSequence(0) = Nothing
                sElementSequence(1) = Nothing
                sElementSequence(2) = Nothing

                sElementComplexType(0) = Nothing
                sElementComplexType(1) = Nothing
                sElementComplexType(2) = Nothing

                sElement(0) = Nothing
                sElement(1) = Nothing
                sElement(2) = Nothing

                mElementSequence = Nothing

                mElementComplexType = Nothing

                mElement = Nothing

                CompiledSchema = Nothing

                NewSchema = Nothing

                SchemaSet = Nothing

                NameSpaceManager = Nothing

                GC.Collect()
            End Try
        End Sub

Depois de criado o arquivo XSD, eu não consigo acessá-lo, pois é informado que o arquivo em questão está sendo usado por outro processo.

O que eu posso fazer para resolver esse problema?

Obrigado

[EduardoS]

Dica 1: Organize melhor/limpe seu código, tem variáveis demais, arrays desnecessárias, variáveis declaradas com "As New" e depois instanciadas de novo e um "For Each" sobrando, com o código mais limpo fica mais fácil de achar os problemas.

Dica 2: Substitua todos os File.funcao por uma instância do FileInfo e chame as funções a partir dele, no fim use essa instância para certificar-se de que o arquivo foi fechado.