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Reading Attribute Values from XML file in VB.NET

Hello Experts,

I am working on a VB.NET Console App in Visual Studio 2012 and i need a little help with reading the attribute values of an element in an XML file. I am working with the XML file that is attached.

Essentially my XML file looks like this. And i would like to pull the value of the Name attribute from all of the SubCategory elements inside of the XML file.

<?xml version="1.0" encoding="US-ASCII" standalone="yes"?>
<MedicalRecords xmlns="Things">
    <Record Archived="false" Locked="false" xmlns="">
        <Label>Lab Report 21</Label>
        <Location>Patients/00dmmnhq/Lab%20Report%2021.tif</Location>
        <Descriptors>
            <Category Name="Item">
               <SubCategory Name="Lab Report"/>
            </Category>
            <Format>image/x-tiff</Format>
            <Keywords/>
        </Descriptors>
        <AddedBy>
            <User Number="10">
                <Label>Sparks, Jeanne (jsp) 10</Label>
                <Location>Users/Sparks%2c%20Jeanne%20%28jsp%29%2010/Identity.xml</Location>
            </User>
            <DateAndTime>2005-09-30T13:11:08.578-04:00</DateAndTime>
        </AddedBy>
        <ReviewedBy>
            <User Number="10">
                <Label>Sparks, Jeanne (jsp) 10</Label>
                <Location>Users/Sparks%2c%20Jeanne%20%28jsp%29%2010/Identity.xml</Location>
            </User>
            <DateAndTime>2005-09-30T13:11:08.578-04:00</DateAndTime>
        </ReviewedBy>
        <TranscribedBy>
            <User Number="10">
                <Label>Sparks, Jeanne (jsp) 10</Label>
                <Location>Users/Sparks%2c%20Jeanne%20%28jsp%29%2010/Identity.xml</Location>
            </User>
            <DateAndTime>2005-09-30T13:11:08.578-04:00</DateAndTime>
        </TranscribedBy>
        <Rights>Copyright 2005 by Haematology-Oncology Associates of Ohio and Michigan, P.C.</Rights>
    </Record>

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Once i have the list of attributes i am looking to hopefully pull them all into an array or something similar so that i can use the following code to create new directories for each one of the values.

If(Not System.IO.Directory.Exists(YourPath)) Then
    System.IO.Directory.CreateDirectory(YourPath)
End If

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Göran Andersson

This should get a list of all the subcategory names:

Dim doc As XDocument = XDocument.Load(fileName)
Dim names As List(Of String) = doc.Root.Elements("Record").Select(Function(n) n.Element("Descriptors").Element("Category").Element("SubCategory").Attribute("Name").Value).ToList()

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robthomas09

ASKER

Hi Goran,

I'm trying the code you suggested inside of the main module here.

Imports System
Imports System.Text
Imports System.Xml

Module Module1

    Sub Main()

        Dim doc As XDocument = XDocument.Load("Records.xml")
        Dim names As List(Of String) = doc.Root.Elements("Record").Select(Function(n) n.Element("Descriptors").Element("Category").Element("SubCategory").Attribute("Name").Value).ToList()

        Dim value As String = String.Join(",", names)
        Console.WriteLine(value)
    End Sub
End Module

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Unfortunately when i go to build the code i am getting an "Object reference not set to an instance of an object" on the following line

Dim names As List(Of String) = doc.Root.Elements("Record").Select(Function(n) n.Element("Descriptors").Element("Category").Element("SubCategory").Attribute("Name").Value).ToList()

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Am I missing a piece of code when i go to test it out?

ASKER CERTIFIED SOLUTION

Göran Andersson

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