Get xml from web services and use in tree view of silver light

private void cmbTaxonomy_SelectionChanged(object sender, SelectionChangedEventArgs e)

{

_objWebService.getTreeOfClassCompleted += new EventHandler(_objWebService_getTreeOfClassCompleted);

_objWebService.getTreeOfClassAsync(cmbTaxonomy.SelectedItem.ToString());

}

const string xmlNodeTextAttName = "Name";

const string xmlNodeTagAttId = "Id";

const string xmlNodeTagClass = "Class";

const string xmlNodeTagRoot = "Root";

void _objWebService_getTreeOfClassCompleted(object sender, getTreeOfClassCompletedEventArgs e)

{

XDocument xDocument = XDocument.Parse(e.Result);

trvHierarchy.Items.Clear();

if (xDocument.Root != null)

if(xDocument.Root.Elements().ToArray().Count()>0)

{

foreach (var VARIABLE in xDocument.Root.Elements().ToArray())

{

if (VARIABLE != null)

{

TreeViewItem parentNodeItem = new TreeViewItem

{

IsExpanded = true,

Header = CreateTreeViewItemHeader(VARIABLE.Attribute(xmlNodeTextAttName).Value, Convert.ToInt64(VARIABLE.Attribute(xmlNodeTagAttId).Value))

};

AddChildItemsInTree(VARIABLE, parentNodeItem);

trvHierarchy.Items.Add(parentNodeItem);

}

}

}

}

private void AddChildItemsInTree(XElement ParentVariable, TreeViewItem parentNodeItem)

{

if(ParentVariable.HasElements)

{

foreach(var variableChild in ParentVariable.Elements().ToArray())

{

if (ParentVariable != null)

{

TreeViewItem childNodeItem = new TreeViewItem

{

IsExpanded = true,

Header = CreateTreeViewItemHeader(variableChild.Attribute(xmlNodeTextAttName).Value, Convert.ToInt64(variableChild.Attribute(xmlNodeTagAttId).Value))

};

//childNodeItem.Header = variableChild.Attribute(xmlNodeTextAttName).Value;

AddChildItemsInTree(variableChild, childNodeItem);

parentNodeItem.Items.Add(childNodeItem);

}

}

}

}