(VB.NET) Traverse Direct Children via FirstChild / NextSibling, or LastChild / PreviousSibling

Demonstrates some ways to iterate over direct child nodes using the FirstChild / NextSibling and LastChild / PreviousSibling methods.

The input XML, available at http://www.chilkatsoft.com/data/fruit.xml, is this:

<root>
    <fruit color="red">apple</fruit>
    <fruit color="green">pear</fruit>
    <veg color="orange">carrot</veg>
    <meat animal="cow">beef</meat>
    <xyz>
        <fruit color="blue">blueberry</fruit>
        <veg color="green">broccoli</veg>
    </xyz>
    <fruit color="purple">grape</fruit>
    <cheese color="yellow">cheddar</cheese>
</root>

Download: Chilkat .NET Assemblies

Dim xml As New Chilkat.Xml()
Dim child As Chilkat.Xml
Dim nextSibling As Chilkat.Xml
Dim prevSibling As Chilkat.Xml

Dim success As Boolean
'  The sample input XML is available at http://www.chilkatsoft.com/data/fruit.xml
success = xml.LoadXmlFile("fruit.xml")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & xml.LastErrorText & vbCrLf
    Exit Sub
End If


'  Iterate over the direct children by using FirstChild / NextSibling
child = xml.FirstChild()
While Not (child Is Nothing )
    TextBox1.Text = TextBox1.Text & child.Tag _
         & " : " & child.Content & vbCrLf
    nextSibling = child.NextSibling()

    child = nextSibling
End While
TextBox1.Text = TextBox1.Text & "-----" & vbCrLf

'  Do the same, but with FirstChild2 / NextSibling2 to avoid
'  creating so many XML object instances:
success = xml.FirstChild2()
While success = true
    TextBox1.Text = TextBox1.Text & xml.Tag & " : " _
         & xml.Content & vbCrLf
    success = xml.NextSibling2()
End While
'  Revert back up to the parent:
xml.GetParent2()

TextBox1.Text = TextBox1.Text & "-----" & vbCrLf

'  Iterate in reverse order using LastChild / PreviousSibling
child = xml.LastChild()
While Not (child Is Nothing )
    TextBox1.Text = TextBox1.Text & child.Tag _
         & " : " & child.Content & vbCrLf
    prevSibling = child.PreviousSibling()

    child = prevSibling
End While
TextBox1.Text = TextBox1.Text & "-----" & vbCrLf

'  Do the same, but with LastChild2 / PreviousSibling2 to avoid
'  creating so many XML object instances:
success = xml.LastChild2()
While success = true
    TextBox1.Text = TextBox1.Text & xml.Tag & " : " _
         & xml.Content & vbCrLf
    success = xml.PreviousSibling2()
End While
'  Revert back up to the parent:
xml.GetParent2()