c# - Linq to XML Read and output XML generated from lookup list -

i trying use xml created lookup list in sharepoint datasource treeview. in form of :

<newdataset>   <test_data>     <id>1</id>     <title>menuitem_1</title>     <child_of />       </test_data>   <test_data>     <id>2</id>     <title>subitem_1</title>     <action>http://www.google.com</action>     <child_of>menuitem_1</child_of>      </test_data>   <test_data>     <id>3</id>     <title>subitem_2</title>     <action>http://www.google.com</action>     <child_of>menuitem_1</child_of>   </test_data>   <test_data>     <id>4</id>     <title>menuitem_2</title>     <child_of />   </test_data>   <test_data>     <id>5</id>     <title>subitem_2_1</title>     <action>http://www.google.com</action>     <child_of>menuitem_2</child_of>   </test_data>   <test_data>     <id>6</id>     <title>subitem_2_2</title>     <action>http://www.google.com</action>     <child_of>menuitem_2</child_of>   </test_data>   <test_data>     <id>7</id>     <title>subitem_2_2_1</title>     <action>http://www.google.com</action>     <child_of>subitem_2_2</child_of>   </test_data> </newdataset> 

there may n tiers, items relate parent via <child_of> element. can't seem figure out how write linq in c# nest menu items properly. friend recommended post here. appreciated.

you this, think long putting production code.

from n in testdata.elements("test_data")                   .aggregate(new dictionary<string, treenode<string>>()                          {{ string.empty, new treenode<string>() }},                         (d, e) =>                         {                             var curnode = new treenode<string>(e.element("id").value);                             d.add(e.element("title").value, curnode);                             d[e.element("child_of").value].addchild(curnode);                             return d;                         })                   .values n.parent == null select n; 

note assumes element has parent key of "empty string" or comes in source list after parent.

personally, factor (especially aggregation) method of own.