Forums: Back End:

I am using a .NET to look through some XML files and show on the page some output if it finds what it is looking for.

I keep getting the error System.Xml.XMLException: Root element is missing.

I have played with this for ages and I am certain the XML is fine.... Could someone lend a hand and see if they can see a problem? Would really appreciate the help.

JTG

Example XML File & Program Code.

<?xml version="1.0" ?> 

- <LogonList>

- <User_logon>

  <Logon_Date>08/05/2008 08:20:28</Logon_Date> 

  <User>whyte_s</User> 

  <Machinename>ST-15086</Machinename> 

  </User_logon>

- <User_logon>

  <Logon_Date>09/05/2008 08:19:05</Logon_Date> 

  <User>whyte_s</User> 

  <Machinename>ST-15086</Machinename> 

  </User_logon>

- <User_logon>

  <Logon_Date>12/05/2008 08:13:06</Logon_Date> 

  <User>whyte_s</User> 

  <Machinename>ST-15086</Machinename> 

  </User_logon>

  </LogonList>

Try

            'create an array of XML files in directory

            Dim Files() As String = Directory.GetFiles(FilePath(), "*.xml")





            Dim strTemp As String

            For Each strTemp In Files



                'create variables for reading XML

                Dim XMLDoc As XmlDocument = New XmlDocument

                Dim m_nodelist As XmlNodeList

                Dim m_node As XmlNode







                XMLDoc.Load(strTemp) 'Load xml file into XMLDoc

                m_nodelist = XMLDoc.SelectNodes("LogonList/User_logon")    'Get list of User_Logon nodes





                'Loop through the file and extract the info if it exists

                For Each m_node In m_nodelist

                    Dim strDate As String = CStr(m_node.ChildNodes.Item(0).InnerText)

                    Dim strUser As String = CStr(m_node.ChildNodes.Item(1).InnerText)

                    Dim strMachine As String = CStr(m_node.ChildNodes.Item(2).InnerText)



                    If strMachine = Pcname() Then

                        Output() = Output & strUser & " on " & strDate & "<br>"

                        Exit For

                    End If



                Next



            Next

        Catch ex As Exception

            'Errors generated by exiting loop so no catch wanted.

            MsgBox(ex.ToString)



        End Try

//edit ...actually I'm talking crap...nm.

What line of that code do you get that error on?

First thing to do, check that it really is trying to parse the content you think it is -- it might be that the XmlDocument.Load method isn't doing what you think.

I should have added. I do get the expected output however its accompanied by the error. I *could* ignore the error but in the past that has not proven wise.

I have tried using a breakpoint on the second last next and stepped in. It does loop through all the xml files checking them but after about 100-130 files have been checked it throws the error.

All the XML files are generated by an application so have identical nodes etc. I tried deleting what I thought might be culprit XML file (the one after the last one it read, as i figured that caused the error) but it still throws the error on the next one anyway.

Hmm...perhaps you should check the output of this line:

Dim Files() As String = Directory.GetFiles(FilePath(), "*.xml")

I checked the output as you suggested and it is only checking the directory it is supposed to.

As I said above, usually after it checks a number of files it seems to crash with that error....well I know why now. someone has manually created an XML file it seems with no data. It cannot have been generated by the system as it would have at least one entry...

So a name.xml file with no data means no elements!

I just so happened to notice a file had 0k size.

Thanks very much for your help both of you. I am getting better at the .NET stuff so before long I will repay your efforts by helping others in the same way

JTG