public void GoBack()
{
if (History.Count == 0)
{
CurrentItems = Orignal;
}
else
{
SunburstDrillDownHistory history = null;
do
{
History.TryPop(out history);
} while (history != null && history.Items.Count() == 1 && history.Items.First() == CurrentItems.First());
CurrentItems = history == null ? Orignal: history.Items;
}
if (OnDrillDownChanged != null)
{
this.OnDrillDownChanged(this, new EventArgs());
}
}