public void MoveToItem(object item)
{
VerifyValidItem(item);
if (IsCurrencyEnabled == false) {
throw new InvalidOperationException("This DataList does not support currency.");
}
int index = _snapShot.IndexOf(item);
CurrentIndex = index;
RaisePropertyChanged("CanMovePrevious");
RaisePropertyChanged("CanMoveNext");
RaisePropertyChanged("CurrentItem");
}