Selecting Child Node of XElement with LINQ Group By

Question

I have some xml in the form:

<Test>
  <Parent Value1="1" Value2="2">
    <Child value3="x"/>
  </Parent>
  <Parent Value1="1" Value2="2">
    <Child value3="y"/>
  </Parent>
  <Parent Value1="a" Value2="b">
    <Child value3="z"/>
  </Parent>
</Test>

I am trying to use xelements and linq to group the child nodes under parent nodes that have the same attribute values. E.g.:

<Test>
  <Parent Value1="1" Value2="2">
    <Child value3="x"/>
    <Child value3="y"/>
  </Parent>
  <Parent Value1="a" Value2="b">
    <Child value3="z"/>
  </Parent>
</Test>

To date, this is what I've got:

    Dim l_xeXML As XElement = <Test>
                                  <Parent Value1="1" Value2="2">
                                      <Child value3=""/>
                                  </Parent>
                                  <Parent Value1="1" Value2="2">
                                      <Child value3=""/>
                                  </Parent>
                                  <Parent Value1="a" Value2="b">
                                      <Child value3=""/>
                                  </Parent>
                              </Test>

    Dim l_xeGROUPED As XElement = <Test>
                                      <%= From l_xeExample As XElement In l_xeXML...<Parent>
                                          Group l_xeExample By Key = New With {Key l_xeExample.@Value1, Key l_xeExample.@Value2} Into Group
                                          Select l_GROUPED = New With {.Value1 = Key.Value1, .Value2 = Key.Value2}
                                          Select <Parent Value1=<%= l_GROUPED.Value1 %> Value2=<%= l_GROUPED.Value2 %>>
                                                     <!-- Can't work out what to put here -->
                                                 </Parent> %>

                                  </Test>

    Debug.Print(l_xeGROUPED.ToString)

On the line <!-- Can't work out what to put here --> , I have tried putting <%= l_xeExample.<Child> %> however I get an error saying that l_xeExample is not within scope.

Can anybody help?

Thanks in advance

Answer 1

This will produce the desired output :

.......
.......
Dim l_xeGROUPED As XElement = 
    <Test>
          <%= From l_xeExample As XElement In l_xeXML...<Parent>
              Group l_xeExample By Key = New With {Key l_xeExample.@Value1, Key l_xeExample.@Value2} 
              Into Parent = Group
              Select <Parent Value1=<%= Key.Value1 %> Value2=<%= Key.Value2 %>>
                         <%= From g As XElement In Parent.<Child>
                             Select g
                         %>
                     </Parent> %>
      </Test>
Debug.Print(l_xeGROUPED.ToString)