XmlTextReader

Question

Hello
I've this sample to read and pass an xml document to a function:

Dim reader As XmlTextReader = Nothing
reader = New XmlTextReader(File.OpenRead("D:\file.xml"))
reader.WhitespaceHandling = WhitespaceHandling.None
pass reader to the function...
If Not reader Is Nothing Then reader.Close()

I've got 2 issues with this,
1/ Need to keep a copy of the whole XML document INTACT in a variable, what kind of variable can hold XML? I don't need any processing/parsing except this switch: WhitespaceHandling.None
Return no Whitespace and no SignificantWhitespace nodes.

2/ I will need to get the XML back and pass to the said function as XmlReader, the point is that once I read the file File.OpenRead("D:\file.xml") will need to close it and won't have access to it anymore, so must keep it in a variable.
Thanks for helping out :)

Answer 1

Hi @OSVBNET ,
You can use the XmlDocument Class to save a copy of the xml file.

    NotInheritable Class XmlDocumentSample  
  
        Private Sub New()  
  
        End Sub  
  
        Shared reader As XmlReader  
        Shared filename As String = "bookdtd.xml"  
  
        Public Shared Sub Main()  
  
  
            Dim eventHandler As New ValidationEventHandler(AddressOf XmlDocumentSample.ValidationCallback)  
  
            Try  
  
                ' Create the validating reader and specify DTD validation.  
                Dim settings As New XmlReaderSettings()  
                settings.DtdProcessing = DtdProcessing.Parse  
                settings.ValidationType = ValidationType.DTD  
                AddHandler settings.ValidationEventHandler, eventHandler  
  
                reader = XmlReader.Create(filename, settings)  
  
                ' Pass the validating reader to the XML document.  
                ' Validation fails due to an undefined attribute, but the   
                ' data is still loaded into the document.  
                Dim doc As New XmlDocument()  
                doc.Load(reader)  
                Console.WriteLine(doc.OuterXml)  
              
            Finally  
  
                If Not (reader Is Nothing) Then  
                    reader.Close()  
                End If  
  
            End Try  
  
        End Sub  
  
        ' Display the validation error.  
        Private Shared Sub ValidationCallback(ByVal sender As Object, ByVal args As ValidationEventArgs)  
            Console.WriteLine("Validation error loading: {0}", filename)  
            Console.WriteLine(args.Message)  
        End Sub  
  
    End Class  

Best Regards.
Jiachen Li

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