private static void OnSelectedValuePathChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
TreeView tree = (TreeView)d;
SelectedValuePathBindingExpression.ClearValue(tree);
tree.UpdateSelectedValue(tree.SelectedItem);
}
private BindingExpression PrepareSelectedValuePathBindingExpression(object item)
{
if (item == null)
{
return(null);
}
Binding binding;
bool useXml = SystemXmlHelper.IsXmlNode(item);
BindingExpression bindingExpr = SelectedValuePathBindingExpression.GetValue(this);
// replace existing binding if it's the wrong kind
if (bindingExpr != null)
{
binding = bindingExpr.ParentBinding;
bool usesXml = (binding.XPath != null);
if (usesXml != useXml)
{
bindingExpr = null;
}
}
if (bindingExpr == null)
{
// create the binding
binding = new Binding();
binding.Source = item;
if (useXml)
{
binding.XPath = SelectedValuePath;
binding.Path = new PropertyPath("/InnerText");
}
else
{
binding.Path = new PropertyPath(SelectedValuePath);
}
bindingExpr = (BindingExpression)BindingExpression.CreateUntargetedBindingExpression(this, binding);
SelectedValuePathBindingExpression.SetValue(this, bindingExpr);
}
return(bindingExpr);
}
